Journal articles on the topic 'Nitrogen fertiliser (varied levels)'
To see the other types of publications on this topic, follow the link: Nitrogen fertiliser (varied levels).
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Nitrogen fertiliser (varied levels).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Rae, DJ, and RE Jones. "Influence of Host Nitrogen Levels on Development, Survival, Size and Population-Dynamics of Sugarcane Mealybug, Saccharicoccus-Sacchari (Cockerell) (Hemiptera, Pseudococcidae)." Australian Journal of Zoology 40, no. 3 (1992): 327. http://dx.doi.org/10.1071/zo9920327.
Full textAbstract:
Nitrogen levels in commercial plots of sugarcane varied over the cane-growing season. However, when adjusted for seasonal effects, nitrogen did not have a detectable effect on the size of mealybug populations on cane. In laboratory experiments, the survival of immature Saccharicoccus sacchari and the size attained at the onset of the oviposition period was influenced by the level of nitrogen fertiliser applied to potted sugarcane. Survival of S. sacchari increased to a maximum at 320 mg L-1 soluble nitrogen in sugarcane and decreased at higher levels, while size increased with increased nitrogen over the whole range of concentrations tested. Nitrogen-driven changes in the abundance of S. sacchari predicted from laboratory data indicate that normal variations in nitrogen concentrations of field-grown sugarcane have little effect on the population dynamics of S. sacchari.
2
Heenan, DP, WJ McGhie, FM Thomson, and KY Chan. "Decline in soil organic carbon and total nitrogen in relation to tillage, stubble management, and rotation." Australian Journal of Experimental Agriculture 35, no. 7 (1995): 877. http://dx.doi.org/10.1071/ea9950877.
Full textAbstract:
The influence of rotation, tillage, stubble management, and nitrogen (N) fertiliser on soil organic carbon (C) and total nitrogen (N) was studied between 1979 and 1993 in a field experiment at Wagga Wagga, New South Wales, on a red earth. The rotations included lupin-wheat (LW), subterranean clover-wheat (SW), and continuous wheat (WW) with and without N fertiliser (100 kg N/ha). At the start of the experiment the soil organic C and N in the surface 10 cm were high following many years of subterranean clover based pasture. The trends in soil organic C varied considerably between treatments from near equilibrium levels for SW direct-drilled and stubble-retained to annual losses of 400 kg/ha for WW conventionally cultivated and stubble burnt. Similarly, total soil N content over time varied from equilibrium levels to highly significant declines of 53 kg/ha. year for WW conventionally cultivated and stubble burnt. Both direct drilling and stubble retention reduced the losses of organic C and N compared with conventional cultivation and burning, with greatest loss occurring when cultivation and stubble burning were combined. SW and LW produced a similar contribution of fixed N to total N product removal, but greater benefits to following wheat crops were provided by SW rotations. Where losses of organic C and N were recorded there was no evidence of equilibrium levels being reached after 14 years.
3
Strong, WM, J. Harbison, RHG Nielsen, BD Hall, and EK Best. "Nitrogen availability in a Darling Downs soil following cereal, oilseed and grain legume crops. 2. Effects of residual soil nitrogen and fertiliser nitrogen on subsequent wheat crops." Australian Journal of Experimental Agriculture 26, no. 3 (1986): 353. http://dx.doi.org/10.1071/ea9860353.
Full textAbstract:
Two dryland wheat crops were grown in 1977 and 1978 following each of 18 cereal, oilseed, or grain legume crops grown in 1976 on a black earth soil on the Darling Downs of Queensland. Combined grain yields of the two crops following the grain legumes fieldpea, lathyrus, lentil and lupin cv. Ultra were higher (P< 0.05) than those following all cereal and oilseed crops except canary seed, safflower and rapeseed cv. Torch. Urea (0-90 kg/ha N), applied to wheat in 1977 on a site adjacent to the crop comparison experiment, had little effect on grain yield in that year. However, in 1978, wheat responded to residues of these applications up to the 50 kg/ha N rate. Variation in wheat yields following the 18 crops appeared to be related to nitrogen (N) supply. The quantity of N assimilated into wheat grain was directly related to the quantity of soil mineral N to a depth of 1.2 m when the 1977 crop was planted. This varied from 37 kg/ha N after oats to 160 kg/ha N after lathyrus. Efficiency of recovery of soil mineral N by the 1977 wheat crop was very low, due probably to the unavailability of N in top soil during the dry winter. Poor availability of N in the top soil was also the most likely cause of a similarly low recovery of fertiliser N applied to the 1977 wheat crop. There was a better apparent recovery of N by the second wheat crop; soil mineral N levels for all treatments had declined to between 17 and 28 kg/ha N after crop harvest. In spite of a low overall efficiency of N uptake by wheat in 1977, more N was assimilated into the grain following legumes (27-39 kg/ha) than following cereals (1 6-2 1 kg/ha), even when fertilised with up to 90 kg/ha N (19 kg/ha). The presence of mineral N in subsoil layers (0.3-0.9 m) following legumes was considered responsible for relatively high grain yields and N uptakes of the following wheat crop in this season of limited growing-season rainfall. Protein concentration of wheat grain was generally higher following grain legumes than following all cereals or oilseeds except safflower. Grain protein concentration was increased by the application of N fertiliser, but fertilised wheat in 1977 generally showed a lower protein content than wheat following grain legumes. However, the second wheat crop following most legumes (except lathyrus) showed a protein content similar to the second wheat crop following N fertiliser application.
4
Furtini, Isabela Volpi, Magno Antonio Patto Ramalho, and Ângela de Fátima Barbosa Abreu. "Implications of selection in common bean lines in contrasting environments concerning nitrogen levels." Crop Breeding and Applied Biotechnology 14, no. 3 (October 2014): 160–65. http://dx.doi.org/10.1590/1984-70332014v14n3a24.
Full textAbstract:
Grain productivities of 100 bean lines were evaluated in the presence and absence of nitrogen fertilizer in order to identify those with high nitrogen use efficiency (NUE) and to determine the correlated response observed in a stressed environment following selection in a non-stressed environment. The genetic and phenotypic characteristics of the lines, as wellas the response index to applied nitrogen, were determined. The average grain productivities at both locations were 39.5% higher in the presence of nitrogen fertilizer, with 8.3 kg of grain being produced per kg of nitrogen applied. NUE varied greatly between lines. Lines BP-16, CVII-85-11, BP-24, Ouro Negro and MA-IV-15-203 were the most efficient and responsive. The results showed that it is possible to select bean lines in stressed and non-stressed environments. It was inferred that common bean lines for environments with low nitrogenav ailability should preferably be selected under nitrogen stress.
5
Sądej, W., and K. Przekwas. "Fluctuations of nitrogen levels in soil profile under conditions of a long-term fertilization experiment." Plant, Soil and Environment 54, No. 5 (May 19, 2008): 197–203. http://dx.doi.org/10.17221/394-pse.
Full textAbstract:
The present study is focused on the correlation between varied long-term fertilization and changes in soil nitrogen concentrations. It was found that all fertilization systems significantly increased the levels of total, mineral and organic nitrogen in the soil profile. Organic fertilizers (manure and slurry) contributed to a more considerable increase in the concentrations of total nitrogen and nitrogen undergoing hydrolysis in 6M HCl, compared to mineral fertilizers. Ammonia nitrogen dominated over nitrate nitrogen among mineral nitrogen forms. Organic fertilization contributed to nitrate nitrogen accumulation, while mineral fertilization to ammonia nitrogen storage. The highest accumulations of nitrate nitrogen and ammonia nitrogen were observed after the application of slurry and manure, respectively. Hydrolyzable nitrogen content and its proportion in total nitrogen generally decreased with soil depth. An increase in the levels of organic nitrogen forms, i.e. nitrogen contained in amino sugars and amino acids as well as ammonia nitrogen from decomposition of amides, amino sugars and amino acids, was conditioned primarily on the application of organic fertilizers, particularly manure. Amino acid-N dominated among hydrolyzable nitrogen compounds (77%), while amino sugar-N accounted for 5.6% only.
6
Virgona, J. M., F. A. J. Gummer, and J. F. Angus. "Effects of grazing on wheat growth, yield, development, water use, and nitrogen use." Australian Journal of Agricultural Research 57, no. 12 (2006): 1307. http://dx.doi.org/10.1071/ar06085.
Full textAbstract:
The effect of grazing by sheep during the late vegetative and early reproductive phases was measured on long-duration wheat crops in 2 experiments on farms in southern NSW. In both experiments, grazed and non-grazed crops were compared with different N-fertiliser strategies. In the first experiment, grazing 40 dry-sheep equivalents (DSE)/ha for 19 days increased grain yield from 2.30 to 2.88 t/ha in a season with a dry early spring. The second experiment, in a more favourable season, compared 6 durations of grazing by an average of 32 DSE/ha. The effects of grazing varied from no yield reduction with 15 days of grazing to a reduction from 5.97 to 3.98 t/ha with 51 days of grazing. In both experiments grazing caused slower crop development, with about 1 day’s delay in anthesis and maturity for every 4–5 days of grazing. Different patterns of water use by grazed and non-grazed crops, combined with delayed development, explained much of the effects of grazing on yield. The soil accumulated more water during grazing, which was used during grain filling when water-use efficiency for grain production was high. Delayed development also allowed grazed crops to respond to later rain. In the second experiment, grazing resulted in a net loss of 38 kg N/ha from the crop. Despite reduced N levels, the grazed crops showed no greater ability than grain-only crops to recover fertiliser N. The effect of the low recovery was that N removed during grazing was not efficiently replaced by fertiliser.
7
Guppy, C. N., C. Edwards, G. J. Blair, and J. M. Scott. "Whole-farm management of soil nutrients drives productive grazing systems: the Cicerone farmlet experiment confirms earlier research." Animal Production Science 53, no. 8 (2013): 649. http://dx.doi.org/10.1071/an12147.
Full textAbstract:
The Cicerone Project included a study of three 53-ha farmlets, each subjected to a different management system. The systems varied first in their input of fertilisers and sown pastures and second in their grazing management. Farmlet A undertook a high level of pasture renovation and had soil fertility targets of 60 mg/kg Colwell phosphorus (P) and 10 mg/kg KCl-40 sulfur (S), while farmlets B and C both had a low rate of pasture renovation and targets of 20 mg/kg P and 6.5 mg/kg S. In addition, both farmlets A and B adopted a flexible rotational grazing regime over the eight paddocks of each farmlet, whereas farmlet C, which had 37 paddocks, adopted intensive rotational grazing. This paper first reviews the literature relating to soil fertility research in the summer-dominant rainfall region of the Northern Tablelands of New South Wales, Australia. It then examines whether the soil fertility targets set for the farmlets were attained and how the consequences of fertiliser management measured in this trial related to earlier research findings. Fertiliser applications, comprising both capital and maintenance rates, were based on soil test results but at times were constrained by the availability of finance. Soil tests over 5 years indicated that only nitrogen (N), P and S varied with time within the farmlets while the other indices of soil fertility remained similar. Phosphorus and S levels increased in response to fertiliser applications whereas N levels responded to increases in legume composition, which was stimulated by the higher P and S levels. Multivariate statistical analyses demonstrated that farmlet productivity was driven by P and S fertility and thus the two farmlets with lower P and S fertility (farmlets B and C) had similar but lower levels of farmlet productivity compared with farmlet A. Significant increases in several measured pasture productivity parameters were observed in response to the higher P and S fertility on farmlet A, especially when climatic conditions were favourable. The results of the Cicerone farmlet experiment confirm the findings of earlier research on the Northern Tablelands, and elsewhere in the high rainfall zone, that has demonstrated that higher soil fertility levels and pasture renovation enhance the productivity of grazing enterprises more than grazing management, without imposing significant risks to the environment.
8
Yeager, Tom, and Geri Cashion. "Controlled-release Fertilizers Affect Nitrate Nitrogen Runoff from Container Plants." HortTechnology 3, no. 2 (April 1993): 174–77. http://dx.doi.org/10.21273/horttech.3.2.174.
Full textAbstract:
Container plant runoff NO3-N levels varied with sampling time and were periodically higher than the 10-ppm federal drinking water standard during 4.5 months following fertilizer application, even though controlled-release fertilizers Nutricote 18N-2.6P-6.6K Osmocote 18N-2.6P-10K, Prokote 20N-1.3P-8.3K, and Woodace 19N-2.6P-10K were used. Leachate collected from containers had a higher NO3-N level than runoff regardless of sampling time. Leachate NO3-N ranged from 278 ppm for Nutricote 3.5 months after application to 6 ppm for Prokote 1 week after application.
9
Mason, MG, and RW Madin. "Effect of weeds and nitrogen fertiliser on yield and grain protein concentration of wheat." Australian Journal of Experimental Agriculture 36, no. 4 (1996): 443. http://dx.doi.org/10.1071/ea9960443.
Full textAbstract:
Field trials at Beverley (19911, Salmon Gums (1991; 2 sites) and Merredin (1992; 2 sites), each with 5 rates of nitrogen (N) and 3 levels of weed control, were used to investigate the effect of weeds and N on wheat grain yield and protein concentration during 1991 and 1992. Weeds in the study were grasses (G) and broadleaf (BL). Weeds reduced both vegetative dry matter yield and grain yield of wheat at all sites except for dry matter at Merredin (BL). Nitrogen fertiliser increased wheat dry matter yield at all sites. Nitrogen increased wheat grain yield at Beverley and Merredin (BL), but decreased yield at both Salmon Gums sites in 1991. Nitrogen fertiliser increased grain protein concentration at all 5 sites-at all rates for 3 sites [Salmon Gums (G) and (BL) and Merredin (G)] and at rates of 69 kg N/ha or more at the other 2 sites [Beverley and Merredin (BL)]. However, the effect of weeds on grain protein varied across sites. At Merredin (G) protein concentration was higher where there was no weed control, possibly due to competition for soil moisture by the greater weed burden. At Salmon Gums (G), grain protein concentration was greater when weeds were controlled than in the presence of weeds, probably due to competition for N between crop and weeds. In the other 3 trials, there was no effect of weeds on grain protein. The effect of weeds on grain protein appears complex and depends on competition between crop and weeds for N and for water at the end of the season, and the interaction between the two.
10
Nassar, Rania M. A., Engy A. Seleem, Gianluca Caruso, Agnieszka Sekara, and Magdi T. Abdelhamid. "The Nitrogen-Fixing Bacteria—Effective Enhancers of Growth and Chemical Composition of Egyptian Henbane under Varied Mineral N Nutrition." Agronomy 10, no. 7 (June 27, 2020): 921. http://dx.doi.org/10.3390/agronomy10070921.
Full textAbstract:
Egyptian henbane (Hyoscyamus muticus L.) plants are rich sources of alkaloids used in pharmaceutical products. Recently, rising efforts have been devoted to reducing mineral fertilizer supply, production cost, and environmental pollution via decreasing the doses of nitrogenous fertilizers and adopting biofertilizer farming systems. Two field experiments were conducted to examine the potential role of N fixing bacteria Azotobacter spp. and Azospirillum spp. on the growth, mineral status, tropane alkaloids, leaf anatomy, and seed yield of Egyptian henbane grown with different levels of mineral nitrogen fertilizer, i.e., 25%, 50%, and 100% of the recommended dose, equal to 30, 60, and 120 kg N ha−1. N fertilizer improved growth, mineral elements, tropane alkaloids, seed yield, and yield components of Egyptian henbane, which showed a gradually rising trend as the rate of N fertilizer increased. High doses of N fertilizer presumably elicited favorable changes in the anatomical structure of Egyptian henbane leaves. The application of 50% N dose plus N fixing bacteria affected Egyptian henbane trials similarly to 100% of recommended N dose. In conclusion, the N fixing bacteria proved to be a sustainable tool for a two-fold reduction in the recommended dose of mineral N fertilizer and the sustainable management of Egyptian henbane nutrition.
11
Mazur, Viktor, Ihor Didur, Viacheslav Tsyhanskyi, and Smiylo Malamaura. "FORMATION OF PRODUCTIVITY OF SUNFLOWER HYBRIDS DEPENDING ON THE LEVEL OF FERTILIZATION AND HUMIDITY CONDITIONS." Agriculture and Forestry, no. 4 (December 18, 2020): 208–20. http://dx.doi.org/10.37128/2707-5826-2020-4-17.
Full textAbstract:
Currently, there is a significant gap between the production and consumption of vegetable oils in Ukraine, as a significant part of them is exported to the European Union. Therefore, in order to quantify the comparative performance of different sunflower hybrids under the influence of different moisture conditions and nitrogen fertilizer rates, this study was conducted. The studied variants included three hybrids of sunflower Hysun 33, Hysun 38 and Pioneer-64A93, five rates of nitrogen fertilizers (0, 60, 120, 180, 240 kg of nitrogen per 1 ha ), arranged randomly in quadruplicate. Field research was conducted for two years under three different conditions of moisture (insufficient, unstable and sufficient) in the research areas of Vinnytsia National Agrarian University. The results of the study showed that the productivity of sunflower hybrids varied greatly in response to the application of nitrogen fertilizers and different humidification conditions. The maximum seed yield of 3,177 t / ha was obtained under conditions of sufficient moisture. Among the studied hybrids, the hybrid Hysun 38, surpassed the other two hybrids, providing a yield of 3.083 t / ha and a seed oil content of 41%. There was an increase in the yield of hybrids with increasing rates of nitrogen fertilizers, and the maximum yield was obtained by applying 180 kg / ha of nitrogen in dr. Studies have shown that the yield potential of hybrid Hysun 38 can be fully used by applying nitrogen fertilizers at a rate of 180 kg / ha in conditions of insufficient moisture. Higher nitrogen levels contributed to the significant formation of vegetative mass, thus balancing in favor of reproductive growth. Achieving a yield plateau with 180 kg / ha of nitrogen fertilizers means that an additional dose of nitrogen fertilizers did not contribute to further yield growth. The presence of a strong correlation between the yield of hybrids and nitrogen norms indicates that the yield depends on the presence of a sufficient amount of nitrogen in the soil. The highest yield was obtained by hybrid Hysun 38 - 3,662 t / ha with the introduction of 180 kg / ha of nitrogen. The oil content in the seeds varied significantly depending on different moisture conditions, hybrids and nitrogen fertilizer rates. The maximum oil content of 42.8% was obtained in conditions of sufficient moisture, in conditions of unstable - 40.9% and in conditions of insufficient - 40.4%
12
Shahbazi, F., S. Falah, and H. R. Eisvand. "Mechanical Damage to Chickpea Seeds as Affected by Npk Fertilization." Cercetari Agronomice in Moldova 47, no. 3 (September 1, 2014): 15–25. http://dx.doi.org/10.2478/cerce-2014-0023.
Full textAbstract:
Abstract The aim of research was to determine the effect of nitrogen (N), phosphorus (P) and potassium (K) fertilizers onthe some physical properties and mechanical damage to chickpea seeds under impact. The martial for tests was from a field experiment with varied levels fertilization with nitrogen (0 and 50 kg/ha, N), phosphorus (0 and 100 kg/ha, P2O5) and potassium (0 and 100 kg/ha, K2O). The variation of the mechanical damage was analyzed depending on the mode of varied fertilization, seed moisture content and impact energy. It was found that the chickpea seeds were bigger with NPK supply. The effects of phosphorus and potassium fertilizers rates on the mechanical damage to chickpea seeds was significant at 1% probability level (P<0.01) and increased its hardness and resilience therefore caused the better resistance to impact damage. Potassium fertilization ratehad the most influence and phosphorus fertilization rate had the least. The effect of the nitrogen fertilizer rate was not significant (P>0.05). Harvesting chickpea seeds at higher moisture content and lower impact energy should give lower breakage when NPK is supplied, as well as when no NPK is supplied.
13
Sha, Chenyan, Jian Wu, Jianqiang Wu, Chunmei Ye, Cheng Shen, Jinghua Su, and Min Wang. "Effects of Different Fertilizers on Soil Microbial Diversity during Long-Term Fertilization of a Corn Field in Shanghai, China." Diversity 15, no. 1 (January 6, 2023): 78. http://dx.doi.org/10.3390/d15010078.
Full textAbstract:
The long-term applications of different fertilizers (chicken manure, swine manure, and organic fertilizer) on the microorganisms of a corn field were investigated. The microbial communities during four periods (seedling, three-leaf, filling and mature periods) were comprehensively studied with molecular biology technology. Results showed that most nutrient contents (organic matter, nitrogen, phosphorus, and potassium) and levels of several heavy metals (As, Pb, and Cr) in the chicken and swine manures were higher than those in the organic fertilizer. The alpha diversity varied during the long-term fertilization, and the chicken manure was the best fertilizer to maintain the abundance of microorganisms. The microbial community of soil changes over time, regardless of the addition of different fertilizers. The correlations between environmental factors and microbial communities revealed that nutrient substances (available nitrogen, available potassium, and NO3-N) were the most significant characteristics with the chicken and swine manures, while organic matter and nitrogen exhibited similar effects on the microbial structure with the organic fertilizer. The Pearson correlations of environmental factors on genus were significantly different in the organic fertilizer tests compared with the others, and Pseudomonas, Methyloligellaceae, Flavobacterium, and Bacillus showed significant correlations with the organic matter. This study will provide a theoretical basis for improving land productivity and sustainable development in corn fields.
14
Ghoneim, Adel M., Gewaily E.E., and Marvet M. A. Osman. "Effects of Nitrogen Levels on Growth, Yield And Nitrogen use Efficiency Of Some Newly Released Egyptian Rice Genotypes." Open Agriculture 3, no. 1 (September 1, 2018): 310–18. http://dx.doi.org/10.1515/opag-2018-0034.
Full textAbstract:
Abstract Application of appropriate level of nitrogen fertilization is a major objective to increase nitrogen use efficiency by rice varieties. Field experiments were conducted during 2016 and 2017 growing seasons to evaluate the efficiency of varying nitrogen fertilizer rates on growth and yield parameters, along with nitrogen use efficiency of some newly released rice varieties (Sakha 108) and some promising lines GZ9399-4-1-1-3-2-2, GZ10101- 5-1-1-1 and GZ10154-3-1-1-1. Five nitrogen levels (i.e. 0, 55, 110, 165 and 220 kg N ha-1) were used. The results from both growing seasons indicated that, Sakha 108 recorded the highest grain yield while GZ10154 and GZ10101 recorded the lowest grain yields. A linear increase in grain yield was observed with continuous rate increase of nitrogen from 0 to 220 kg ha-1, while 220 kg N ha-1 treatment showed maximum grain yield followed by 165 kg N ha-1, with control as minimum. Agronomic nitrogen use efficiency (AE) for studied rice genotypes varied significantly, and ranged from 3.63 to 32.9 and from 2.72 to 34.12 kg grain yield produced per kg of nitrogen applied in 2016 and 2017 respectively. Across N levels, GZ9399 recorded the highest values of AE for the nitrogen fertilizer rate of 165 kg N ha-1 in both seasons.
15
Guazzelli, Laura, Frederick S. Davies, and James J. Ferguson. "Fertilization Rate and Growth of `Hamlin' Orange Trees Related to Preplant Leaf Nitrogen Levels in the Nursery." HortScience 31, no. 4 (August 1996): 613e—614. http://dx.doi.org/10.21273/hortsci.31.4.613e.
Full textAbstract:
Our objectives were to determine if leaf N concentration in citrus nursery trees affected subsequent growth responses to fertilization for the first 2 years after planting and how N fertilizer rate affected soil nitrate-N concentration. `Hamlin' orange [Citrus sinensis (L.) Osb.] trees on `Swingle' citrumelo rootstock [C. paradisi Macf. × P. trifoliata (L.) Raf.] were purchased from commercial nurseries and grown in the greenhouse at differing N rates. Three to five months later trees were separated into three groups (low, medium, high) based on leaf N concentration and planted in the field in Oct. 1992 (Expt. 1) or Apr. 1993 (Expt. 2). Trees were fertilized with granular material (8N–2.6P–6.6K) with N at 0 to 0.34 kg/tree yearly. Soil nitrate-N levels were also determined in Expt. 2. Preplant leaf N concentration in the nursery varied from 1.4% to 4.1% but had no effect on trunk diameter, height, shoot growth, and number or dry weight in year 1 (Expt. 1) or years 1 and 2 (Expt. 2) in the field. Similarly, N fertilizer rate had no effect on growth during year 1 in the field. However, trunk diameter increased with increasing N rate in year 2 and reached a maximum with N at 0.17 kg/tree yearly. Shoot number during the second growth flush in year 2 was much lower for nonfertilized vs. fertilized trees. Leaf N concentrations increased during the season for trees with initially low levels even for trees receiving low fertilizer rates. Soil nitrate-N levels were highest at the 0.34-kg rate, and lowest at the 0.11-kg rate. Nitrate-N levels decreased rapidly in the root zone within 2 to 3 weeks of fertilizing.
16
Naik, M. Ramesh, S. Hemalatha, A. P. K. Reddy, K. V. Naga Madhuri, V. Umamahesh, and S. Rakesh. "Efficient Need Based Nitrogen Management in Rabi Maize (Zea mays L.) using Leaf Colour Chart Under Varied Planting Density." International Journal of Bio-resource and Stress Management 13, no. 6 (June 30, 2022): 586–94. http://dx.doi.org/10.23910/1.2022.2881a.
Full textAbstract:
The field experiments were conducted for two consecutive rabi seasons (November –March) of 2017–18 and 2018–19 at the Wet land farm of S.V. Agricultural College, Tirupati to calibrate leaf colour chart (LCC) for increasing growth yield, nitrogen uptake under varied plant density to establish and evaluate threshold leaf colour greenness as a guide for in-season need based fertilizer N in maize. Research results indicated that the planting density, nitrogen levels and LCC threshold values significantly influenced all the growth and yield attributes, yield and nitrogen uptake. Plant height, days required to 50% tasselling and silking, cob yield, harvest index and nitrogen uptake increased significantly with increase in plant density i.e., 1,11,111 plants ha-1 with application of fertilizer nitrogen at higher dose i.e. 40 kg ha-1 and by using higher LCC threshold value (LCC 5) in different splits. Whereas, leaf area planr-1, cob girth, number of kernels rows cob-1 and number of kernels cob-1 was lessened significantly with increase in planting density, however it was increased with application of nitrogen at higher rate i.e., 40 kg ha-1 by using higher LCC threshold value (LCC 5) at various splits. Eventually, experimental results manifested that, fine-tuning of N dose and time of application by number of splits which synchronize the crop demand was the best management strategy for sustainable crop growth, production and productivity of maize.
17
Waterer, D. "Petiole sap NO3-N testing as a method for monitoring nitrogen nutrition of potato crops." Canadian Journal of Plant Science 77, no. 2 (April 1, 1997): 273–78. http://dx.doi.org/10.4141/p96-091.
Full textAbstract:
Petiole sap NO3-N concentrations were tested as a means for monitoring crop nitrogen (N) status and N fertilizer responses in potatoes. An ion specific electrode was used to monitor sap NO3-N concentrations of three varieties of potatoes grown with differing amounts of N fertilizer in 1993–1995. Plots provided with varying amounts of fertilizer N applied prior to planting or as a split application were sampled on six occasions through the growing season. Sap NO3-N levels were positively correlated with petiole dry matter NO3-N levels. Petiole sap NO3-N levels reflected rates and timing of N fertilizer application. Sap NO3-N levels in the three cultivars showed similar changes with time after planting and increasing N fertilizer rates. However, sap NO3-N levels measured under a particular set of conditions were unique for each cultivar. The correlation between yields and sap NO3-N levels varied with the sampling date and cultivar. Recommendations were developed for critical sap NO3-N concentrations at various stages in the development of the three cultivars. Key words: Ion specific electrode, nitrate, petiole, nitrogen, tissue testing, Solanum tuberosum
18
Wali, Pardeep, Vinod Kumar, and J. P. Singh. "Effect of soil type, exchangeable sodium percentage, water content, and organic amendments on urea hydrolysis in some tropical Indian soils." Soil Research 41, no. 6 (2003): 1171. http://dx.doi.org/10.1071/sr01090.
Full textAbstract:
Urea has emerged as one of the most extensively used sources of nitrogen fertiliser in recent years because of its low cost per unit nitrogen. Urea hydrolysis in soils is an enzymatic decomposition process by the enzyme urease. The effects of soil type, exchangeable sodium percentage, moisture regime, and organic manures and their levels on the kinetics of urea hydrolysis were studied in a series of laboratory incubation experiments at 25 ± 1�C. Urea transformation followed first-order kinetics, and the first-order rate constants for soils varied from 0.0321 to 0.1182/h. The rate of urea hydrolysis in the different soils increased with greater clay content and followed the order: Gulkani clay loam > Dadupur loam > Hisar sandy loam > Jakhol silty clay loam > Bawal loamy sand > Balsamand sand. Increasing the exchangeable sodium percentage in soils decreased the rate of urea hydrolysis both at field capacity and flooded conditions (2 cm standing water). Application of vermicompost, sheep manure, poultry manure, pig manure, and urban waste to soil at the 1% level increased the rate of hydrolysis over the untreated soil.
19
Mason, MG, and IC Rowland. "Effect of amount and quality of previous crop residues on the nitrogen fertiliser response of a wheat crop." Australian Journal of Experimental Agriculture 32, no. 3 (1992): 363. http://dx.doi.org/10.1071/ea9920363.
Full textAbstract:
Burr medic (Medicago polymorpha cv. Circle Valley) at 3 sowing rates (3, 12, and 50 kg/ha), narrow leaf lupins (Lupinus angustifolius cv. Illyarrie) at 2 sowing rates (30 and 100 kg/ha, with the high rate sown early or late) and oats (Avena sativa cv. Winjardie) at 2 sowing rates (20 and 60 kg/ha, with the high rate sown early or late), were planted on a deep, infertile siliceous sand at Badgingarra in 1988, to produce residues of varying quantity and quality. Residues produced (minus seed) varied in quantity from 0.70 t/ha (medic 3 kg/ha) to 4.22 t/ha (lupins 100 kg/ha sown early) when measured in late summer. Carbon to nitrogen ratios (C/N) ranged from 37.3 to 58.5 (medic), 28.3 to 40.4 (lupins), and 78.6 to 112.0 (oats). Seed present in the residues ranged from 0.18 to 0.47 t/ha (medic) and from 0.32 to 0.57 t/ha (lupins). The ranges in C/N values were 8.3-9.3 (medic) and 9.4-10.0 (lupin). There was no grain in the oats residues. The residues were incorporated into the soil during the sowing operation of a wheat crop in 1989. Subplots of 6 rates of N as ammonium nitrate (0, 14, 27, 54, 82, and 163 kg N/ha) were included in each block. Wheat dry matter and grain yields were higher following lupins and medic than following oats, and although there were large responses to N fertiliser following all 1988 crops, the N application had little effect on the difference between oats and legumes. In the absence of N fertiliser, yields and N uptake by the 1989 wheat crop were higher following lupins than following medic, due to hardseededness of medic seeds. There were no significant differences within 1988 crop groups. There were good correlations between dry matter and grain yield of wheat without N fertiliser and C/N value of the residues. The correlations were better when seed was not included in the calculation (r2 = 0.86 and 0.80, respectively) than when the seed was included (r2 = 0.79 and 0.64). Similar correlations were obtained between dry matter and grain yields and total N content of the residues. Correlations were lower when seed was omitted (r2 = 0.64 and 0.75) than when it was included (r2 = 0.70 and 0.81). Yields decreased with increasing C/N and increased with total N content of the residues. Wheat grain N concentrations fell with the first increment of N fertiliser, which produced a large yield increase, but rose to high levels at high rates of N.
20
Herridge, D. F., M. J. Robertson, B. Cocks, M. B. Peoples, J. F. Holland, and L. Heuke. "Low nodulation and nitrogen fixation of mungbean reduce biomass and grain yields." Australian Journal of Experimental Agriculture 45, no. 3 (2005): 269. http://dx.doi.org/10.1071/ea03130.
Full textAbstract:
Apparent nodulation failures and associated low grain yields have been reported for commercial mungbean (Vigna radiata) crops in southern Queensland and northern New South Wales. We therefore conducted on-farm surveys of 40 commercial mungbean crops in the region in which symbiotic traits, i.e. nodulation and nitrogen fixation, and biomass and grain yield were monitored. Effects of bradyrhizobial inoculation and inoculation methods on mungbean and soybean (Glycine max) symbiosis and yield were determined in experiments at 3 sites in northern New South Wales. Thirty-four of the 35 mungbean crops assessed for nodulation were nodulated. The relationship between soil nitrate to a depth of 90 cm at sowing and mungbean nodulation was not significant. However, at low-to-moderate soil nitrate levels (<100 kg N/ha), the mean nodule score was 1.6, compared with 0.5 at high (>100 kg N/ha) soil nitrate levels. Soil nitrate had a negative effect on the percentage of mungbean nitrogen derived from nitrogen fixation (%Ndfa). Mean %Ndfa values for soil nitrate levels <50, >50–100 and >100 kg N/ha were 35, 22 and 19% respectively. Grain yields of the surveyed mungbean crops varied from 0.3 to 2.1 t/ha, and were correlated with shoot dry matter. Grain yield was not significantly correlated either with sowing soil nitrate, nodule score or %Ndfa. In the inoculation experiments, mungbean did not nodulate as well as soybean, producing about one-third the number of nodules. Both species responded to inoculation with increased nodulation, although data from one of the sites suggested that responses during early growth of mungbean were not maintained during pod-fill. Effects of inoculation on mungbean %Ndfa were marginal. Average increases were 9%, based on natural 15N abundance, and 6%, based on the ureide method. Soybean %Ndfa, on the other hand, responded strongly to inoculation, with increases of 56 (15N) and 77% (ureide). Inoculation increased mungbean crop N by an average of 10% and grain yield by 6%, compared with responses to fertiliser nitrogen of 31% (crop N) and 10% (grain yield). For soybean, inoculation increased crop nitrogen by 43% and grain yield by 7%, similar to responses to fertiliser nitrogen of 45 (crop N) and 5% (grain yield). These results suggest that inoculated mungbean was N-limited and that inoculation of mungbean using current technology may be somewhat ineffectual. We concluded that low nodulation and nitrogen fixation of commercial mungbean most likely results from the suppressive effects of nitrate and/or insufficient numbers of bradyrhizobia in the soil. When low symbiosis and low soil nitrate are combined, N is likely to limit crop growth, and potentially grain yield. Suggested strategies for improving mungbean nodulation and nitrogen fixation in the northern grains belt include selection of more symbiotically competent plant and bradyrhizobial genotypes and more effective utilisation of established soil populations of mungbean bradyrhizobia.
21
Laurence, RCN, JD Armour, RK Shepherd, LR Loader, and MJ Dwyer. "Nitrogen fertilizer requirements of irrigated potatoes on the Atherton Tableland, North Queensland." Australian Journal of Experimental Agriculture 25, no. 4 (1985): 954. http://dx.doi.org/10.1071/ea9850954.
Full textAbstract:
Seven field experiments were carried out during 1980 and 1981 to determine the nitrogen fertilizer requirements of potatoes grown in basaltic krasnozem soils in North Queensland. Rates of 0, 40, 80, 160 and 320 kg nitrogen/ha were compared in all experiments. Comparisons of urea and ammonium nitrate as fertilizer forms and basal and split application methods were also carried out in four of the experiments. Total yields of fresh tubers from nil-nitrogen plots varied from 18.1 to 29.7 t/ha and nitrogen applications increased these yields at all sites to levels varying from 136 to 325% of the control plots. Ninety-eight per cent of maximum yields calculated from quadratic functions were produced by rates of basally applied urea nitrogen varying from 108 to 205 kg/ha. These rates were poorly correlated with relative yields and topsoil (0-20 cm depth) nitrate nitrogen but were well correlated with nitrogen in 20-50 cm depth. Nitrogen application increased the average tuber weights from 135 to 179 g but reduced the specific gravity of tubers. Splitting nitrogen applications reduced average tuber weights.
22
Akinola, J. O. "NITROGEN RETENTION IN RAPIDLY-GROWING STEERS GIVEN UREA SUPPLEMENTED DIETS." Nigerian Journal of Animal Production 9, no. 1 (January 16, 2021): 21–27. http://dx.doi.org/10.51791/njap.v9i1.2252.
Full textAbstract:
"Shika" (indigenous, V,) and "Ngala" (introduction, V2) varieties of elephant grass (Pennisetum purpureum Schum.) field planted at 60 x 90, 60 x 60 or 60 x 30 cm spacing and fertilized at 0, 100, 200 or 400kg N/ha/yr, were examined for dry matTer (DM) yield, crude protein (CP) content, CP yield, nitrogen (N) recovery and stand persistence at Shika during the 1975 and 1976 growing seasons. The highest DM yield resulted from 60 x 30 cm spacing/400kg N combination but the 60 x 60 cm spacing (27,800 plants/ha) with 200kg N appeared optimum for yield. V produced 4.3 to 21.0t DM and V2 2.8 to 17.41 DM/ha/yr over the range of population densities and fertilizer levels investigated. DM yield per kg N applied rose with increasing population density (V, only) and decreasing N rate, the highest value of 49kg being recorded for V t. Mean herbage CP content varied from 7.0% without N to 9.7% with 400kg N/ha but the highest value of 11.0% was obtained from V2 planted at 60 x 90cm. For both grasses, N increased annual CP yield 1.2— 4.5—Fold. The highest apparent fertilizer N recovery of 76.3% occurred at 200kg N/ha while plants survived best at 60 x 60cm spacing.
23
Paula, Iancu, Păniță Ovidiu, and Soare Marin. "Evaluation of Drought Tolerance Indices and Nitrogen Fertilization for Some Groundnut (Arachis Hypogaea L.) Genotypes." Agricultural Science 1, no. 1 (December 23, 2019): p18. http://dx.doi.org/10.30560/as.v1n1p18.
Full textAbstract:
Water is essential to maximize crop yield and quality. This natural resource has assumed huge importance, especially in the warmest areas, where drought and environmental degradation has affected agricultural production. In order to identify drought tolerance of some groundnut genotypes and to investigate the relationships between seed yield, quality and drought tolerance indices a study was made using 10 promising genotypes. The experiment was carried out during 2014-2017 and sowed under randomized block design with four replicates. It included three factors: two levels of irrigation (a1 – non - irrigated and a2 - irrigated), two levels of fertilization (b1 – non-fertilized and b2 - 100 active Nitrogen/ha) and genotype (C1-C10). Seed yield depending on the influence of the factor, varied from 535.95 Kg/ha (non-irrigated) to 2020.95 Kg/ha (irrigated); from 1055.30 Kg/ha (non-fertilized) to 1501 Kg/ha (fertilized) and from 1111.30 Kg/ha to 1388 Kg/ha depending on genotype. Same influence factors for protein content varied from 25.65% (irrigated) to 28.61% (non-irrigated); from 26.33% (non-fertilized) to 27.93% (fertilized) and from 25.59% to 28.52% depending on genotype. Stress susceptibility index (SSI) varied from 0.964 to 1.040; Stress Tolerance Index (STI) from 0.138 to 0.435; Mean Productivity (MP) from 883.5 to 1616.0; Geometric Mean Productivity (GMP) from 750.3 to 1332.7; Tolerance index (TOL) from 933.0 to 1844.0; Harmonic Mean (HM) from 637.2 to 1099.0; Yield Index (YI) 0.777 to 1.308 and Yield Stability Index (YSI) from 0.236 to 0.309. High values of SSI, STI, YI, DI, RDI and SSPI indicate drought tolerance and those variants present high stability.
24
Guazzelli, Laura, Frederick S. Davies, and James J. Ferguson. "Fertilization Rate and Growth of `Hamlin' Orange Trees Related to Preplant Leaf Nitrogen Levels in the Nursery." HortTechnology 6, no. 4 (October 1996): 383–87. http://dx.doi.org/10.21273/horttech.6.4.383.
Full textAbstract:
Our objectives were to determine the effects of leaf N concentration in citrus nursery trees on subsequent growth responses to fertilization for the first 2 years after planting and the impact of N fertilizer rate on soil NO3-N concentration. `Hamlin' orange [Citrus sinensis (L.) Osb.] trees on `Swingle' citrumelo rootstock [C. paradisi Macf. × P. trifoliata (L.) Raf.] were purchased from commercial nurseries in Apr. 1992 (Expt. 1) and Jan. 1993 (Expt. 2) and were grown in the greenhouse at differing N rates. Five months later, trees for each experiment were separated into three groups (low, medium, and high) based on leaf N concentration and were planted in the field in Oct. 1992 (Expt. 1) or Apr. 1993 (Expt. 2). Trees were fertilized with granular material (8N-2.6P-6.6K-2Mg-0.2Mn-0.12Cu-0.27Zn-1.78Fe) with N at 0, 0.11, 0.17, 0.23, 0.28, or 0.34 kg/tree per year. Soil NO3-N levels were determined at 0- to 15- and 16- to 30-cm depths for the 0.11-, 0.23-, and 0.34-kg rates over the first two seasons in Expt. 2. Preplant leaf N concentration in the nursery varied from 1.4% (Expt. 1) to 4.1% (Expt. 2) but had no effect on trunk diameter, height, shoot growth and number, or dry weight in year 1 (Expt. 1) or years 1 and 2 (Expt. 2) in the field. Similarly, fertilizer rate in the field had no effect on growth during year 1 in the field. However, trunk diameter increased with increasing N rate in year 2 and reached a maximum with N at 0.17 kg/tree per year but decreased at higher rates. Shoot number during the second growth flush in year 2 was much lower for nonfertilized vs. fertilized trees at all rates, which had similar shoot numbers. Nevertheless, leaf N concentrations increased during the season for trees with initially low levels, even for trees receiving low fertilizer rates. This suggests translocation of N from other organs to leaves. Soil NO3-N levels were highest for the 0.34-kg rate and lowest at the 0.11-kg rate. Within 2 to 3 weeks of fertilizing, NO3-N levels decreased rapidly in the root zone.
25
Szabó, Atala, Seyed Mohammad Nasir Mousavi, Csaba Bojtor, Péter Ragán, János Nagy, Attila Vad, and Árpád Illés. "Analysis of Nutrient-Specific Response of Maize Hybrids in Relation to Leaf Area Index (LAI) and Remote Sensing." Plants 11, no. 9 (April 28, 2022): 1197. http://dx.doi.org/10.3390/plants11091197.
Full textAbstract:
Leaf area index (LAI) indicates the leaf area per ground surface area occupied by a crop. Various methods are used to measure LAI, which is unitless and varies according to species and environmental conditions. This experiment was carried out in three different nitrogen ranges (control, 120 kg N ha−1, and 300 kg N ha−1) + PK nutrient levels, with five replications used for leaf area measurement on seven different maize hybrids. Hybrids had different moisture, protein, oil, and starch contents. N (1, 2) + PK treatments had a desirable effect on protein, starch, and yield. P0217 LAI had a minimal response at these fertiliser levels. LAI for Sushi peaked at different dates between control and fertiliser treatments. This result showed that Sushi has an excellent capacity for LAI. LAI values on 15 June 2020 showed minimum average values for all hybrids, and it had a maximum average values on 23 July 2020. LAI had maximum performance between the average values treatments in Sushi, Armagnac, Loupiac, and DKC4792 on 15 June 2020. This study also provides insights for examining variably applied N doses using crop sensors and UAV remote-sensing platforms.
26
Mason, MG, WM Porter, and WJ Cox. "Effect of an acidifying nitrogen fertiliser and lime on soil pH and wheat yields. 1. Soil effects." Australian Journal of Experimental Agriculture 34, no. 2 (1994): 237. http://dx.doi.org/10.1071/ea9940237.
Full textAbstract:
Three long-term trials were commenced in 1980 at Merredin, Wongan Hills, and Newdegate to investigate the effect of an acidifying fertiliser containing 17.5% nitrogen (N) and 7.6% phosphorus (P) (based on ammonium sulfate and ammonium phosphate) on soil pH, soil acidity related problems, and wheat grain yields under continuous cropping. Treatments were 3 rates (kg/ha) of N + P applied with the cereal seed (nil; 17.5 N + 7.6 P; 35 N + 15.2 P), with or without 3 t/ha of ground limestone (with or without MgSO4, KCl, Moo3) applied in 1980. Two extra treatments were 2 rates of limestone (70, 140 kg/ha) topdressed with the cereal crop each year along with the low and high N + P fertiliser treatments, respectively. This paper reports soil properties for the first 10 years of the trials. In the acidic Merredin soil (pH 4.3), there was minimal effect of N + P fertiliser on soil pH. The pH was slightly reduced at 0-10 cm depth. At Wongan Hills, soil pH at 0-10 cm depth was reduced over time by N + P application from 4.8 to 4.2. At Newdegate, only the high rate of N + P reduced pH over time, from 4.6 to 4.3 at 0-10 cm. Limestone at 3 t/ha in 1980 increased soil pH at 0-10 cm depth at all 3 sites; however, in all cases pH fell with time. Limestone applied at 70 or 140 kgha with each N + P application increased pH at 0-10 cm depth by 0.1-0.4, 0.1-0.4, and 0.3-0.9 pH units at Merredin, Wongan Hills, and Newdegate. Soil aluminium (Al) concentrations (extracted in 0.01 mol CaCl2/L) were generally low at Wongan Hills and Newdegate in the absence of N + P fertiliser. These levels rose after N + P application to 4 and 2 �g/g at 0-10 cm depth at Wongan Hills and Newdegate. Soil A1 concentrations at Merredin were high, particularly in the subsoil: 3-5, 9-13, and 23-29 �g/g in the 0-10, 10-20, and 20-40 cm depths. With the high rate of N + P, A1 concentration rose to 10 �g/g at 0-10 cm. Application of 3 t/ha of limestone reduced this to <1-2 �g/g. Application of 140 kg/ha of limestone with the high N + P fertiliser rate lowered soil A1 concentration at 0-10 cm. Extra acid that accumulated in treated plots compared with control plots varied from -34.7 kmol/ha (acid-neutralised) for the treatment at Merredin receiving only 3 t lime/ha in 1980 to 23.8 kmol/ha for the treatment at Wongan Hills receiving high N + P. With the treatments receiving lime only, the amounts of acid neutralised were only 82, 66, and 58% of those predicted at Merredin, Wongan Hills, and Newdegate, respectively. Acid accumulation in the 3 treatments receiving high N + P was within the predicted range at Wongan Hills, as it was for the treatment receiving high N + P plus 3 t lime/ha in 1980 at both Merredin and Newdegate. However, for the treatments receiving only high N + P or high N + P plus 140 kg lime/ha. year at these 2 sites, the acid accumulation rates were less than predicted. Levels of exchangeable cations in the soil were highest at Wongan Hills and lowest at Newdegate. Application of N + P decreased Ca concentration at all sites and reduced the concentration of exchangeable Mg at Wongan Hills. Lime applied at 3 t/ha increased the concentrations of exchangeable Ca and Mg at all sites. There were no effects of treatments on concentrations of exchangeable K or sodium.
27
Shrestha, Shukra Raj, Sarita Manandhar, Bedanand Chaudhary, Bibek Sapkota, Rudra Bhattarai, and Suraya Prasad Adhikari. "Response of Wheat Genotypes to Different Levels of Nitrogen." Journal of Nepal Agricultural Research Council 2 (December 30, 2016): 9–14. http://dx.doi.org/10.3126/jnarc.v2i0.16115.
Full textAbstract:
A field experiment was conducted using six genotypes of wheat (Triticum aestivum L.) for response to different levels of nitrogen (N) use. The experiment was laid out in split plot design with four levels (0, 50, 100 and 150 kg N ha-1) as main plots and six wheat genotypes (BL 3623, BL 3629, BL 3872, NL 1008, NL 1055 and Vijay, a check variety) as sub-plots. Grain yield and other yield components increased linearly in response to N concentrations in both seasons. Only two parameters: days to heading (DOH) and days to maturity (DTM) varied significantly (p ≤ 0.05) among wheat genotypes in both the years. None of the parameters showed interaction effects in both seasons. Vijay showed highest grain yield of 3.12 t ha-1 in 2013 with the application of 100 kg N ha-1, and 3.23 t ha-1 in 2014 with 150 kg N ha-1. Spike length, productive tillers m-2, number of spikes m-2 and test weight were greater with higher N rates. The straw yield of wheat fertilized with 150 kg N ha-1 was the highest in Vijay (4.35 t ha-1) and BL 3872 (4.33 t ha-1), respectively. Vijay with 100 kg N ha-1 produced the highest number of productive tillers m-2 (276.33) in 2013 and 296.00 with the application of 150 kg N ha-1 in 2014.
28
Gourley, Cameron J. P., Warwick J. Dougherty, David M. Weaver, Sharon R. Aarons, Ivor M. Awty, Donna M. Gibson, Murray C. Hannah, Andrew P. Smith, and Ken I. Peverill. "Farm-scale nitrogen, phosphorus, potassium and sulfur balances and use efficiencies on Australian dairy farms." Animal Production Science 52, no. 10 (2012): 929. http://dx.doi.org/10.1071/an11337.
Full textAbstract:
Efficient and effective nutrient management decisions are critical to profitable and sustainable milk production on modern Australian dairy farms. Whole-farm nutrient balances are commonly used as nutrient management tools and also for regulatory assessment on dairy farms internationally, but are rarely used in Australia. In this study, nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) imports and exports were measured during a standardised production year on 41 contrasting Australian dairy farms, representing a broad range of geographic locations, milk production, herd and farm size, reliance on irrigation, and soil types. The quantity of nutrients imported varied markedly – with feed and fertiliser generally the most substantial imports – and were principally determined by stocking rate and type of imported feed. Milk exports were the largest source of nutrient exports. Nitrogen balance ranged from 47 to 601 kg N/ha.year. Nitrogen-use efficiency ranged from 14 to 50%, with a median value of 26%. Phosphorus balance ranged from –7 to 133 kg P/ha.year, with a median value of 28 kg P/ha. Phosphorus-use efficiencies ranged from 6 to 158%, with a median value of 35%. Potassium balances ranged from 13 to 452 kg K/ha, with a median value of 74 kg K/ha; K-use efficiency ranged from 9 to 48%, with a median value of 20%. Sulfur balances ranged from –1 to 184 kg S/ha, with a median value of 27 kg S/ha; S-use efficiency ranged from 6 to 110%, with a median value of 21%. Nitrogen, P, K and S balances were all positively correlated (P < 0.001) with stocking rate and milk production per ha. Poor relationship between P, K and S fertiliser inputs and milk production from home-grown pasture reflected the already high soil fertility levels measured on many of these farms. The results from this study demonstrate that increasing milk production per ha will be associated with greater nutrient surpluses at the farm scale, with the potential for greater environmental impacts. We suggest that simplified and standardised nutrient balance methodologies should be used on dairy farms in Australia to help identify opportunities for improvements in nutrient management decisions and to develop appropriate industry benchmarks and targets.
29
Turpin, J. E., D. F. Herridge, and M. J. Robertson. "Nitrogen fixation and soil nitrate interactions in field-grown chickpea (Cicer arietinum) and fababean (Vicia faba)." Australian Journal of Agricultural Research 53, no. 5 (2002): 599. http://dx.doi.org/10.1071/ar01136.
Full textAbstract:
Soil in which nodulated legumes are growing often contains more nitrate nitrogen (N) than soil in which unnodulated legumes or non-legumes are growing. There is conjecture, however, as to whether the extra or ‘spared’ N is due to reduced use of soil N by the legume or to net mineralisation of legume root and nodular N. We report results of a field experiment to quantify and compare, at different levels of soil-N supply, N2 fixation, and soil-N use by chickpea (Cicer arietinum) and fababean (Vicia faba). Wheat (Triticum aestivum) was included as a non-N2-fixing control. Plants of the 3 species were grown on a low-nitrate Vertosol with fertiliser N rates of 0, 50, and 100 kg/ha (0N, 50N, and 100N), applied 6 weeks before sowing. Samples were collected at sowing and at 64, 100, 135, and 162 days after sowing (DAS) for analysis of soil nitrate, root, and grain dry matter (DM) and N and shoot DM, N, and 15N. The latter was used to estimate the percentage (%Ndfa) and total N fixed by the 2 legumes. Soil nitrate levels to a depth of 1.8 m at sowing were 11–17 kg N/ha (0N), 41–55 kg N/ha (50N), and 71–86 kg N/ha (100N). Grain yields of the 2 legumes were unaffected by soil-N supply (fertiliser N treatment), being 2.0–2.4 t/ha for chickpea and 3.7–4.6 t/ha for fababean. Wheat grain yields varied from 1.6 t/ha (0N) to 4.8 t/ha (100N). Fababean fixed more N than chickpea. Values (total plant including roots) were 209–275 kg/ha for fababean and 146–214 kg/ha for chickpea. Corresponding %Ndfa values were 69–88% (fababean) and 64–85% (chickpea). Early in crop growth, when soil N supply was high in the 100N treatment, fababean maintained a higher dependence on N2 fixation than chickpea (Ndfa of 45% v. 12%), fixed greater amounts of N (57 v. 16 kg/ha), and used substantially less soil N (69 v. 118 kg/ha). In this situation, soil N sparing was observed, with soil nitrate levels significantly higher in the fababean plots (P < 0.05) than under chickpea or wheat. At the end of growth season, however, there were no crop effects on soil nitrate levels. Soil N balances, which combined crop N fixed as inputs and grain N as outputs, were positive for the legumes, with ranges 80–135 kg N/ha for chickpea and 79–157 kg N/ha for fababean, and negative for wheat (–20 to –66 kg N/ha). We concluded that under the starting soil nitrate levels in this experiment, levels typical of many cropping soils in the region, high-biomass fababean and chickpea crops will not spare significant amounts of soil N. In situations of higher soil nitrate and/or smaller biomass crops with less N demand, nitrate sparing may occur, particularly with fababean.
30
Akhtar, Muhammad Naeem, Tanveer Ul-Haq, Fiaz Ahmad, Muhammad Imran, Wazir Ahmed, Abdul Ghaffar, Muhammad Shahid, et al. "Application of Potassium along with Nitrogen under Varied Moisture Regimes Improves Performance and Nitrogen-Use Efficiency of High- and Low-Potassium Efficiency Cotton Cultivars." Agronomy 12, no. 2 (February 17, 2022): 502. http://dx.doi.org/10.3390/agronomy12020502.
Full textAbstract:
Low nitrogen-use efficiency (NUE) is a serious issue for cotton production and environmental sustainability in arid climates. A pot study was conducted to evaluate the effect of K nutrition on NUE and performance of low- and high-K-efficiency cotton cultivars under two moisture regimes. Treatments included two soil moisture levels—i.e., normal irrigation, 100% available water content (AWC); reduced irrigation, 50% AWC—three levels of nitrogen (N)—i.e., 0, 375, and 750 mg N pot−1—and two K levels, i.e., 0 and 208 mg K pot−1. Results reveal that 208 mg K pot−1 application with nitrogen significantly enhanced the N-use efficiency, growth, and yield attributes of both cotton cultivars compared with sole N fertilization. Similarly, the combined application of NK @ 375 N + 208 K mg pot−1 caused up to 83% increase in NUE under AWC50% and AWC100%, as compared with NK control (0 N + 0 K). Compared with the control, imposed low-moisture stress caused a decrease of 13.9% in stomatal conductance (gs), 2.5% in transpiration rate (E), and 6.5% in net photosynthetic rate (PN), respectively. The physiological water use efficiency (PN/E) decreased by 13.2% under AWC50%. Applied NK @ 375 N:208 K, mg pot−1 caused 27.39 and 27.56% improvement in the PN/E in HKE and LKE cultivars under AWC50%, respectively. The HKE cultivar, i.e., CIM-554, maintained the highest gs and PN than FH-901, that was low-K-efficiency cultivar. The study suggests that varietal selection and adequate K fertilization have the prospects to improve NUE and save considerable quantities of fertilizer and irrigation water in cotton production under arid environments.
31
Kaplan, M., H. Kale, K. Karaman, and A. Unlukara. "Influence of different irrigation and nitrogen levels on crude oil and fatty acid composition of maize (Zea mays L.)." Grasas y Aceites 68, no. 3 (September 8, 2017): 207. http://dx.doi.org/10.3989/gya.0222171.
Full textAbstract:
The effect of irrigation and nitrogen fertilizer levels on the crude oil and fatty acid composition of maize cultivars was studied. Three levels of irrigation (50, 75 and 100% of field capacity) and nitrogen (100, 200 and 300 kg·ha-1) were used for treatment groups. After harvest, the crude oils were extracted and fatty acid profiles were determined by Gas Chromatography system. The study was repeated for two years and the interaction effects of fertilizer and irrigation were determined. Our results show that the crude oil content was affected positively by the fertilizer and the irrigation applications. As expected, the most abundant fatty acid was linoleic and the harvest year did not alter it. The highest linoleic acid content value was obtained with a 50% field capacity and 300 kg·ha-1 fertilizer treatment combination. In addition, fatty acid contents varied with the changing of interaction effects except for myristic and palmitic acid. Oleic acid was the second abundant fatty acid in the oil samples and the lowest oleic acid value was obtained with a 50% field capacity and 300 kg·ha-1 fertilizer treatment combination. Oleic acid content tended to increase with 75% field capacity but 100% field capacity treatment decreased in it.
32
Price, G. W., R. P. Voroney, and C. Chong. "Crop performance on soils receiving annual papermill biosolid amendments with and without supplementary nitrogen." Canadian Journal of Soil Science 89, no. 3 (May 2, 2009): 269–79. http://dx.doi.org/10.4141/cjss08014.
Full textAbstract:
Nitrogen availability is often a limiting factor for optimum crop growth on agricultural soils amended with papermill biosolids (PB). The objective of our study was to evaluate the effect on corn (Zea mays L.) and soybean (Glycine max L.) production of adding supplementary nitrogen fertilizer to soils amended with increasing rates of PB. Papermill biosolids were applied annually on four agricultural soils in southern Ontario, Canada. Treatments included three rates of PB (50, 100, and 150 Mg ha-1), combined with four levels of nitrogen fertilizer [crop recommended [CR], [CR] + 0.5 kg N Mg-1 PB, [CR] + 1.0 kg N Mg-1 PB, and [CR] + 1.5 kg N Mg-1 PB]. In addition, non-amended plots were also established receiving either (a) zero PB and zero nitrogen fertilizer or (b) zero PB and [CR] nitrogen fertilizer only. All the plots received the same treatment combinations, i.e., PB × N, each year for the duration of the study. In corn, [CR] nitrogen fertilizer was insufficient to satisfy plant growth and PB decomposition requirements. Supplementary nitrogen fertilizer at a rate of 1.0 kg N Mg-1 PB was generally required to maintain or increase corn grain production relative to the control plots receiving the [CR] nitrogen fertilizer only. Corn grain yield increases ranged from 1000 to 6000 kg ha-1 relative to the control at some of the research sites. The optimum rate of supplementary nitrogen fertilizer varied by soil texture (location) and year. In contrast, production of soybean did not require high supplementary nitrogen fertilizer, or in some cases any, in order to maintain or increase yields at most locations. Our study shows that nitrogen fertility management had a greater impact on yields in production systems planted to corn than soybeans while receiving annual PB amendments. No residual effects on corn yield or corn grain protein content were observed after PB amendments were stopped.Key words: Papermill biosolids, carbon:nitrogen ratio, corn, soybean, nitrogen fertilizer
33
Sarker, Uttam Kumer, Md Romij Uddin, Md Delwar Hossain, Shahanaz Begum, and A. B. M. Raqibul Hasan. "Nitrogen management in boro rice using chlorophyll meter (SPAD) under sub-tropical condition." Archives of Agriculture and Environmental Science 7, no. 2 (June 25, 2022): 166–73. http://dx.doi.org/10.26832/24566632.2022.070204.
Full textAbstract:
Nitrogen deficiency in rice has so far received limited attention in Bangladesh. Balanced fertilization is a pre-requisite for better rice production and it is necessary to determine optimum combination of fertilizer dose and varieties. The field experiment was carried out during the period from November 2020 to May 2021 at the Agronomy Field Laboratory, Bangladesh Agricultural University (BAU), Mymensingh to study the SPAD value and yield performance of boro rice varieties at different nitrogen levels. The experiment comprised of four boro rice varieties viz., BRRI dhan28, BRRI dhan58, BRRI dhan74, BRRI dhan81 and four level of nitrogenous fertilizers viz. 50 kg N ha-1, 100 kg N ha-1, 150 kg N ha-1 and 200kg N ha-1. The experiment was laid out in a randomized complete block design with three replications. SPAD value ranged from 34.01 to 42.12 for variety and 37.81 to 42.15 for nitrogen application, while leaf nitrogen ranged from 2.98 to 3.67 % for variety and 2.94 to 3.48%. The yield contributing parameter varied significantly with variety and nitrogen rate. The highest grain yield (6.13 t ha-1) was found in BRRI dhan58 and the lowest (3.89 t ha-1) was observed in BRRI dhan28. In terms of fertilizer management, the highest grain yield (5.35 t ha-1) was obtained due to the application of 150 kg N ha-1 and the lowest grain yield (4.72 t ha-1) was recorded from50 kg N ha-1. The interactive effect of variety and fertilizer application exerted that the yield of BRRI dhan58 with 150 kg N ha-1 was the highest (6.59 tha-1) and the lowest performance (3.42 tha-1) in grain yield was found in BRRI dhan28 with 50 kg N ha-1. Thus, the variety BRRI dhan58 with 150 kg N ha-1 was superior for attaining the highest yield.
34
Holford, ICR, BM Haigh, and IG Ferris. "Atrazine persistence and phytotoxicity on wheat as affected by nitrogen and rotation-induced changes in soil properties." Australian Journal of Agricultural Research 40, no. 6 (1989): 1143. http://dx.doi.org/10.1071/ar9891143.
Full textAbstract:
Wheat growing in a rotation experiment on an alkaline black earth was severely damaged by atrazine residues, whereas wheat in an adjacent experiment on a slightly acid red clay, was undamaged. Atrazine at 1.8 kg a.i, ha-1 had been applied to both sites nine months before wheat sowing. Nitrogen fertilizer had also been applied as split-plot treatments to the previous crop in each rotation sequence. There were four rotations, each comprising grain sorghum with either lucerne, an annual grain legume, long fallow, or continuous cereal growing.There were significant rotation effects on soil organic matter, pH, mineral nitrogen and residual atrazine. Organic carbon was highest, and soil pH and atrazine were lowest in the lucerne rotation, while the opposite occurred in the long fallow treatment. Atrazine concentration was positively correlated with pH and negatively correlated with organic carbon. The numbers of dead plants on the black earth were positively correlated with atrazine levels, but mortality was lowered by increasing mineral nitrogen at any particular level of atrazine.Wheat yields varied from zero in two continuous cereal plots to over 3.0 t ha-1 in a long fallow plot, and were highly correlated with mineral nitrogen levels. At any level of nitrogen, however, wheat yields were depressed by increasing levels of atrazine. The very large yield response to nitrogen, whether from soil or fertilizer, resulted from its dual beneficial effect of lowering plant mortality and improving the nitrogen status of the surviving plants.These results show that in a wheat crop following atrazine-treated sorghum, significant atrazine damage may occur on soils of pH > 64, that atrazine persistence and phytotoxicity will increase as the pH increases, but that phytotoxicity will decrease as soil nitrogen fertility increases. Lucerne rotations will lower atrazine persistence by decreasing soil pH and increasing organic matter, and will lower phytotoxicity by raising soil nitrogen.
35
Sharma, D. K., and D. R. Sharma. "Sustainable use of poor quality water with proper scheduling of irrigation and nitrogen levels for a rice crop." Water Science and Technology 40, no. 2 (July 1, 1999): 111–14. http://dx.doi.org/10.2166/wst.1999.0099.
Full textAbstract:
Over-exploitation of groundwaters to meet the water requirements for rice-wheat systems is causing both a fall in groundwater levels and their quality deterioration in semi-arid parts of India. Adoption of rice-wheat cropping systems by the farmers using poor quality (sodic) waters for irrigation may adversely affect soil health and thereby reduce crop yield. Adoption of an irrigation schedule coupled with optimum nitrogen doses can be advantageous for sustaining yields of rice in these areas. Strategies for optimum use of these inputs has to be based on the knowledge of soil-water-nutrient-plant interactions evolved through field studies. In order to develop such relations, studies involving several combinations of irrigation levels and nitrogen doses were conducted on rice crops at Kaithal (India), and their effect on biomass, yield, water and nitrogen use efficiency (NUE) were studied during 1993 and 1994. Irrigation schedules were based on the period of submergence ranging from 0 to 6 days. The nitrogen doses varied from 0 to 180 kg ha−1. Both irrigation and nitrogen had a positive effect on yield, which increased from 1729 kg ha−1 (continuous submergence without fertilizer) to 4522 kg ha−1 (irrigation at 3 days disappearance of water with 180 kg N ha−1. At 60 kg N ha−1, NUE varied from 35.4 to 40.9 kg ha−1 grain per kg of N. Further increase in the dose of N upto 180 kg ha−1 however resulted in a decline in NUE. Nitrogen and irrigation had a positive influence on applied water efficiency (AWE). Under continuous submerged conditions, the beneficial effect of N on AWE was observed only up to 120 kg ha−1. But at lower levels of irrigation (3 and 6 days disappearance of water), these effects continued even up to 180 kg ha−1. The results of this study indicated that there is a possibility of using the sodic water (up to residual sodium carbonate [RSC] of 8 meq/l) for growing rice provided the crop is irrigated with an appropriate irrigation scheduling with the higher dose of N under conditions of > 50 cm monsoon rainfall.
36
Fernandez-Salvador, Javier, Bernadine C. Strik, and David R. Bryla. "Response of Blackberry Cultivars to Fertilizer Source during Establishment in an Organic Fresh Market Production System." HortTechnology 25, no. 3 (June 2015): 277–92. http://dx.doi.org/10.21273/horttech.25.3.277.
Full textAbstract:
Blackberry (Rubus ssp. Rubus) cultivars, three trailing types (Marion, Black Diamond, and Obsidian) and one semierect type (Triple Crown), were studied for their response to different types of fertilizer from 2011–12, at a certified organic, grower collaborator site located in Jefferson, OR. Plants were fertilized at a target rate of 50 lb/acre nitrogen (N) each spring using three different sources: 1) a liquid fish and molasses blend (4N–0P–1.7K); 2) pelletized soy (Glycine max) meal (8N–0.4P–1.7K); and 3) pelletized, processed poultry litter (4N–1.3P–2.5K). Plants were drip irrigated, and weeds were managed using a polypropylene, permeable landscape fabric (weed mat). Plant responses were greatly affected by cultivar, whereas the effects of fertilizer type were relatively minor. ‘Triple Crown’ produced the greatest yield in both years, whereas ‘Black Diamond’ and ‘Marion’ had the lowest yield in 2011 and 2012, respectively. ‘Triple Crown’ fruit had the highest percent soluble solids and were the least firm in 2011, whereas ‘Marion’ fruit were the least firm in 2012. Harvest date, within year, affected the fruit quality variables measured in all cultivars. Most soil nutrient levels were within the recommended range for all fertilizer treatments, except for boron (B), which declined to deficient levels in the second year. Fertilizer type had no effect on soil nutrient levels other than fertilization with the fish and molasses blend product increased soil potassium and sodium. Soil nutrient levels were affected by cultivar but varied by year for many nutrients. Primocane leaf tissue nutrient concentrations were above or within recommended standards for most nutrients, except for magnesium (Mg), calcium (Ca), and B, which, depending on the cultivar, were below standards. Over the 2-year study, the blackberry cultivars responded similarly to the three types of organic fertilizer. However, the cost of N varied from $8.16/lb for the liquid fish and molasses blend, $5.35/lb for the pelletized soy meal, and $2.54/lb for the pelletized, processed poultry litter. Supplemental fertilization with B, Mg, and Ca would be required with each fertilizer studied to maintain recommended soil fertility levels.
37
Viketoft, Maria, Laura G. A. Riggi, Riccardo Bommarco, Sara Hallin, and Astrid R. Taylor. "Type of organic fertilizer rather than organic amendment per se increases abundance of soil biota." PeerJ 9 (May 7, 2021): e11204. http://dx.doi.org/10.7717/peerj.11204.
Full textAbstract:
Addition of organic amendments is a commonly used practice to offset potential loss of soil organic matter from agricultural soils. The aim of the present study was to examine how long-term addition of organic matter affects the abundance of different soil biota across trophic levels and the role that the quality of the organic amendments plays. Here we used a 17-year-old fertilization experiment to investigate soil biota responses to four different organic fertilizers, compared with two mineral nitrogen fertilizers and no fertilization, where the organic fertilizers had similar carbon content but varied in their carbon to nitrogen ratios. We collected soil samples and measured a wide range of organisms belonging to different functional groups and trophic levels of the soil food web. Long-term addition of organic and mineral fertilizers had beneficial effects on the abundances of most soil organisms compared with unfertilized soil, but the responses differed between soil biota. The organic fertilizers generally enhanced bacteria and earthworms. Fungi and nematodes responded positively to certain mineral and organic fertilizers, indicating that multiple factors influenced by the fertilization may affect these heterogeneous groups. Springtails and mites were less affected by fertilization than the other groups, as they were present at relatively high abundances even in the unfertilized treatment. However, soil pH had a great influence on springtail abundance. In summary, the specific fertilizer was more important in determining the numerical and compositional responses of soil biota than whether it was mineral or organic. Overall, biennial organic amendments emerge as insufficient, by themselves, to promote soil organisms in the long run, and would need to be added annually or combined with other practices affecting soil quality, such as no or reduced tillage and other crop rotations, to have a beneficial effect.
38
Strong, W. M., R. C. Dalal, J. E. Cooper, J. A. Doughton, E. J. Weston, and G. T. McNamara. "Sustaining productivity of a Vertisol at Warra, Queensland, with fertilisers, no-tillage or legumes 4. Nitrogen fixation, water use and yield of chickpea." Australian Journal of Experimental Agriculture 37, no. 6 (1997): 667. http://dx.doi.org/10.1071/ea97018.
Full textAbstract:
Summary. Continuous cereal cropping in southern Queensland and northern New South Wales has depleted native soil nitrogen fertility to a level where corrective strategies are required to sustain grain yields and high protein content. The objective of this study was to examine the performance of chickpea in chickpea–wheat rotations in terms of yields, water use and N2 fixation. The effects of sowing time and tillage practice have been studied. Chickpea grain yields varied from 356 kg/ha in 1995 to 2361 kg/ha in 1988; these were significantly correlated with the total rainfall received during the preceding fallow period and crop growth. Almost 48% of total plant production and 30% of total plant nitrogen were below-ground as root biomass. Mean values of water-use efficiency for grain, above-ground dry matter, and total dry matter were 5.9, 14.2 and 29.2 kg/ha.mm, respectively. The water-use efficiency for grain was positively correlated with the total rainfall for the preceding fallow and crop growth period although cultural practices modified water-use efficiency. The potential N2 fixation was estimated to be 0.6 kg nitrogen/ha.mm from 1992 total dry matter nitrogen yields assuming all of the nitrogen contained in chickpea was derived from the atmosphere. Sowing time had a much larger effect on grain yield and N2 fixation by chickpea than tillage practice (conventional tillage and zero tillage) although zero tillage generally increased grain yields. The late May–early June sowing time was found to be the best for chickpea grain yield and N2 fixation since it optimised solar energy use and water use, and minimised frost damage. Nitrogen fixation by chickpea was low, less than 40% nitrogen was derived from atmosphere, representing less than 20 kg nitrogen/ha.year. The potential for N2 fixation was not attained during this period due to below-average rainfall and high soil NO3-N accumulation because of poor utilisation by the preceding wheat crop. Increased soil NO3-N due to residual from fertiliser N applied to the preceding wheat crop further reduced N2 fixation. A simple soil nitrogen balance indicated that at least 60% of crop nitrogen must be obtained from N2 fixation to avoid continued soil nitrogen loss. This did not occur in most years. The generally negative soil nitrogen balance needs to be reversed if chickpea is to be useful in sustainable cropping systems although it is an attractive cash crop. Sowing time and zero tillage practice, possibly combined with more appropriate cultivars, to enhance chickpea biomass, along with low initial soil NO3-N levels, would provide maximum N2 fixation.
39
SALO, T. "Effects of band placement and nitrogen rate on dry matter accumulation, yield and nitrogen uptake of cabbage, carrot and onion." Agricultural and Food Science 8, no. 2 (January 2, 1999): 157–232. http://dx.doi.org/10.23986/afsci.5624.
Full textAbstract:
Adequate nitrogen (N) nutrition is essential for producing high vegetable yields of good quality. Fertilizer N not taken up by the plants is, however, economically wasteful and can be lost to the environment. Therefore the efficient use of N fertilizer, involving accurate estimation of crop N demand, choice of application method and timing of N fertilization, is an important research area. The effects of band placement and rate of N fertilization on inorganic N in the soil and the dry matter accumulation, yield and N uptake of cabbage, carrot and onion were studied in a three-year field experiment between 1993 and 1995. The plants were sampled during the growing season to determine the dry matter accumulation and plant N concentration. The inorganic N in the soil was determined during the growing period and after harvest. The N uptake was 3.8 kg, 1.6 kg and 2.5 kg per ton of edible yield of cabbage, carrot and onion, respectively. At the highest yield levels the N uptake including crop residues was 300 kg ha-1, 150 kg ha-1 and 120 kg ha-1 in cabbage, carrot and onion, respectively. In cabbage, almost 50% of N was in crop residues, whereas in carrot and onion only about 30% of N was in crop residues. Nitrogen uptake from non-fertilized soil varied from 29 to 160 kg ha-1, depending on the growing season and the crop. Cabbage and carrot utilised soil N efficiently, usually taking up more than 100 kg ha-1 from non-fertilized soil. Onion, on the contrary, utilised soil N relatively poorly, usually less than 50 kg ha-1 from non-fertilized soil. The rate of N uptake was low with all crops in early summer. After one month, N uptake increased in cabbage and onion. This uptake continued until harvest, i.e. mid-August for onion and early September for cabbage. Nitrogen uptake by carrot started rapidly only two months after sowing and continued until harvest at the end of September. High N rates often resulted in high N concentrations and N uptakes, but growth was not necessarily increased. One month after fertilization, most of the N placed was still near the original fertilizer band and at the depth of 5-10 cm. At that time, broadcast N was at a depth of 0-5 cm. After harvest the soil mineral N content was generally low, i.e. below 25 kg ha-1 at the depth of 0-60 cm. Onion was an exception with poor growth in 1994, when soil mineral N after the highest N rate was 80 kg ha-1 at a depth of 0-60 cm after harvest. The placement distance in the cabbage experiment, 7.5 cm in the side and 7 cm below cabbage transplants, resulted in lower plant growth and N uptake than broadcasting of N at the beginning of the growing periods 1993 and 1994. Towards harvest differences between application methods decreased, although in 1993, placement of N still led to 6% lower cabbage yields than broadcasting of N. In 1993, high N rates increased cabbage dry weight and N uptake towards harvest, and this effect was more pronounced when N was broadcast. In 1994, soil N mineralisation was high, and only non-fertilized cabbages took up less N than fertilized plants. Carrot was remarkably insensitive to N fertilization. Carrot yields were similar with and without N fertilizers. Band placement and N rate did not affect carrot growth and N uptake. In 1993, band placement and high rates of N increased onion growth and bulb yield more than broadcasting. In 1994, onion growth was poor and treatments did not affect plant N concentrations or growth. Apparent recovery of fertilizer N was increased in 1993 by low N rates or band placement. This result that band placement of N does not much affect vegetable growth is in agreement with most previous studies. With onion, probably due to the sparse root system, positive effects of N placement are most likely to be found.;
40
Sichone, Richard, and Alice M. Mweetwa. "Soil Nutrient Status and Cowpea Biological Nitrogen Fixation in a Maize-Cowpea Rotation Under Conservation Farming." Journal of Agricultural Science 10, no. 6 (May 6, 2018): 136. http://dx.doi.org/10.5539/jas.v10n6p136.
Full textAbstract:
This paper reports the impacts of a four-year maize-cowpea rotation under conservation farming on selected soil chemical, physical and biological properties with or without 100 kg/ha of Nitrogen: Phosphorus: Potassium: Sulphur (10:20:10:65) compound fertilizer. The study took advantage of an already established 4-year maize-cowpea rotation site and a maize monocrop field from which soil samples were collected for selected chemical, physical and biological analyses, and for setting up a greenhouse experiment for the determination of biological nitrogen fixation capabilities of cowpea. The results suggest that maize-cowpea rotations and addition of fertilizer influence particular chemical, physical and biological attributes of the soil in a varied manner. Rotating maize and cowpea has no influence on soil reaction, soil organic carbon, micronutrients, and exchangeable bases except for potassium. However, the addition of fertilizer to the maize-cowpea rotation reduces total nitrogen, while increasing the levels of sulphur and phosphorus in both the rotation and maize monocrop. Soil bulk density, total porosity and infiltration rate are not influenced by the maize-cowpea rotation with or without fertilizer amendment. Rotating maize with cowpea without the addition of fertilizer can result in an increase in plant available water, an observation needing further study. It can also be concluded that maize-cowpea rotations can reduce microbial biomass, regardless of fertilizer amendment, thus suggesting a need to understand maize and cowpea rhizopheric attributes affecting microbial biomass levels. Under the current conditions, the amount of biologically fixed nitrogen by cowpea is reduced by the application of fertilizer but not influenced by the rotation. Since these findings are based on four-year crop rotation, it is being recommended that further work be conducted to continue monitoring soil so as to factor in the effect of length of time.
41
Wiedenfeld, Robert, B. Scully, Marvin Miller, Jonathan Edelson, and Jiandong Wang. "FOLIAR NITROGEN EFFECTS ON ONION PRODUCTION AND DAMAGE BY THRIPS AND PURPLE BLOTCH." HortScience 25, no. 8 (August 1990): 864a—864. http://dx.doi.org/10.21273/hortsci.25.8.864a.
Full textAbstract:
Purple blotch (Alternari a porri) and thrips (Thrips tabaci) can seriously reduce yields of short day onions in South Texas. The level of injury caused by these organisms is influenced by the concentration of nitrogen in leaf tissue. Lower levels of tissue nitrogen increase susceptibility to A. porri but decrease susceptibility to thrips. The purpose of this study was to evaluate the effect of tissue N levels on joint susceptibility of 4 onion cultivars to A. porri and thrips. Foliage was fertilized at 0, 4, 8, 12 or 16 lbs N/ac/wk for 6 weeks. Nitrogen concentrations in onion leaves varied over time and by leaf age, but showed very little effect due to foliar fertilization. Significant differences in thrips were noted among cultivars, but not among leaf N concentrations with cultivars. Purple blotch outbreak occurred late in the growing season and was not related to leaf N levels. Total N uptake failed to respond to foliar fertilization, therefore overall use efficiency of the foliar N applied averaged only about 10% relative to the amount taken up in the check plots.
42
Hinesley, L. Eric, Layne K. Snelling, C. Ray Campbell, D. K. Roten, and Jeff Hartzog. "Nitrogen Increases Fresh Weight and Retail Value of Fraser Fir Christmas Trees." HortScience 35, no. 5 (August 2000): 860–62. http://dx.doi.org/10.21273/hortsci.35.5.860.
Full textAbstract:
Abies fraseri (Pursh) Poir. Christmas trees were fertilized for 5 years with four levels of N (0, 56, 113, or 170 kg·ha–1 per year) in spring, fall, or equally split between spring and fall. Nitrogen did not affect leader length, number of leaders, or bud frequency on the upper (distal) portion of the leader. Nitrogen increased bud frequency on the lower (proximal) 20 cm of the leader in only 1 of 3 years of measurement. All application schedules increased the number of apical buds on branches, whereas the number of lateral buds was increased only by spring applications. Nitrogen increased tree fresh weight and retail value as well as weight, length, and surface area of needles. Foliar N concentrations in the fall varied with fertilization schedule, and were higher in November than in October.
43
Saleh H. Byari, Saleh H. Byari. "Effect of Pozzolan and Nitrogen Fertilizer in Reducing Irrigation Water and Soil Moisture Stress in Three Eggplant Cultivars (solanum melongina)." journal of King Abdulaziz University - Meteorology, Environment and Arid Land Agriculture Sciences 23, no. 2 (January 20, 2012): 3–11. http://dx.doi.org/10.4197/met.23-2.1.
Full textAbstract:
Two field experiments were carried out during 2009 and 2010 seasons to study the effects of pozzolan, nitrogen fertilization levels, (50, 75, 100, and 125 kg N/ha) and four irrigation intervals (2, 4, 6, and 8 days) on fruit yield, yield components and chemical proprieties of 3 eggplant cultivars (black beauty, long purple and top bell) in a split split split plot design with three replications. The results indicated that pozzolan treatment significantly increased plant height, leaf area/ plant, no. of fruits/plant and fruit yield/ha besides total soluble solids (TSS) and vitamin C in fruit compared with the pare land (without pozzolan). Increasing irrigation interval significantly reduced plant height, leaf area/plant, no. of fruits /plant, fruit yield/ha and increased TSS, and Vitamin C in fruits. As nitrogen fertilizer increased, plant height, leaf area, no. of fruits/plant and fruit yield/ha significantly increased also TSS, and Vitamin C in fruits increased. Eggplant cultivars significantly varied in their response to pozzolan, irrigation interval and nitrogen fertilizer treatments. Black beauty cultivar significantly dominated the other cultivars in fruit yield/ ha.
44
Blackshaw, Robert E., and Randall N. Brandt. "Nitrogen Fertilizer Rate Effects on Weed Competitiveness is Species Dependent." Weed Science 56, no. 5 (October 2008): 743–47. http://dx.doi.org/10.1614/ws-08-065.1.
Full textAbstract:
Information on nitrogen fertilizer effects on crop–weed competitive interactions might aid in developing improved weed management programs. A controlled environment study was conducted to examine the effect of three N rates on the competitive ability of four weed species grown with wheat. The four weed species were chosen to represent species that varied in their growth responsiveness to nitrogen (N): Persian darnel (low), Russian thistle (low), redroot pigweed (high), and wild oat (high). Wheat and each weed species were grown in a replacement series design at N rates of 60, 120, and 240 mg N kg−1soil. The competitive ability of the low N-responsive species, Persian darnel and Russian thistle, was not influenced by N rate, supporting our hypothesis that N rate would have little effect on the competitiveness of species responding minimally to N. Conversely, the competitiveness of the high N-responsive species redroot pigweed progressively improved as N rate increased. However, wild oat competitiveness was unaffected by N fertilizer rate. There is some evidence from this study to suggest that fertilizer management strategies that favor crops over weeds deserve greater attention when weed infestations consist of species known to be highly responsive to higher soil N levels. Information gained in this study will be used to advise farmers of the importance of strategic fertilizer management in terms of both weed management and crop yield.
45
Schultz, JE. "Crop production in a rotation trial at Tarlee, South Australia." Australian Journal of Experimental Agriculture 35, no. 7 (1995): 865. http://dx.doi.org/10.1071/ea9950865.
Full textAbstract:
A crop rotation trial was established in 1977 on a hard-setting red-brown earth at Tarlee, South Australia, to monitor the long-term effect of intensive and traditional rotations on soil properties and crop production. The rotations involve wheat alternating with cereals, grain legumes, pasture, and fallow. There are 3 stubble + tillage treatments: remove stubble + cultivate, retain stubble + cultivate, retain stubble + no tillage. Three rates of nitrogen (0,40, 80 kg N/ha as ammonium nitrate) are applied to the wheat. Grain yield varied with seasonal conditions, and water use efficiencies were up to 10 kg/ha. mm. In the more productive rotations, wheat grain yields expressed as a percentage of potential yield tended to increase over time. The best wheat yields were always in rotations that included a grain legume or legume pasture, with additional yield increases in all rotations coming from the use of N fertiliser. By comparison with rotation and N fertiliser effects, there was little effect of the stubble + tillage treatments on grain yield. Most of the yield variations were related to differences in tiller density or grains per ear, with grain weight remaining relatively constant over all seasons. There was a tendency for grain legume yields to decrease over the latter years of the trial, and this was attributed to the build-up of plant diseases through growing the same species on the same plot every second year. Overall, faba beans were the highest yielding grain legume, and the wheat-beans rotation, with 80 kg N/ha on the wheat, gave highest total grain production. Data for residue remaining after harvest indicate that in some years there is less than the desired minimum levels to give adequate protection against erosion, so any grazing of the residues must be carefully managed.
46
Pearson, CJ, H. Kemp, AC Kirby, TE Launders, and C. Mikled. "Responsiveness to seasonal temperature and nitrogen among genotypes of kikuyu, paspalum and bermuda grass pastures of coastal New South Wales." Australian Journal of Experimental Agriculture 25, no. 1 (1985): 109. http://dx.doi.org/10.1071/ea9850109.
Full textAbstract:
Three experiments were carried out to test the hypotheses that (a) there are quantitative differences in growth rate and quality between newly registered cultivars and older cultivars in response to changes in temperature and fertility, and (b) responsiveness to temperature varies between sites because cultivars acclimatize to their current environment. Performance in simulated swards indicated that potential productivity was highest from bermuda grass (Cynodon x Burton Pearson). This was, however, a poor indicator of performance in the field, where yield of bermuda grass was depressed by weeds whereas that of kikuyu (Pennisetum clandestinum) was unaffected. In the field, a newly registered kikuyu, cv. Crofts, outyielded bermuda grass and paspalum (Paspalum dilatatum) either alone or when combined with lucerne. A further experiment compared cvv. Crofts, Whittet and common kikuyu at three levels of nitrogen at three sites. Peak growth rates were the same at all locations but Crofts outyielded the other genotypes by 60, 13 and 18% at Bega (37�S.), Camden (34�S.) and Taree (32�S.) respectively. Average growth rates varied seasonally and were correlated with temperature (r > 0.9). Analysis of temperature responsiveness (kg/ha.�C) indicated that responsiveness varied consistently between genotypes at any location. Furthermore, the base temperature (the temperature below which there was negligible growth) was the same for all genotypes at any location but it increased with increasing latitude. That is, there was a tendency to greater dormancy with increasing coldness of location. Nitrogen responsiveness was the same for all genotypes and sites. Seasonal variations in digestibility and mineral concentrations in kikuyu, bermuda grass and paspalum were similar in the field and in simulated swards; quality was the same in all kikuyu genotypes. Calcium, magnesium and nitrogen concentrations of plant tops (but not phosphorus and potassium concentrations) increased with increasing rates of application of nitrogen fertilizer.
47
Holt, N. W. "Forage intake and grazing times of yearling beef steers grazing nitrogen-fertilized Russian wildrye (Psathyrostachys junceus)." Canadian Journal of Animal Science 72, no. 2 (June 1, 1992): 375–87. http://dx.doi.org/10.4141/cjas92-045.
Full textAbstract:
Forage dry matter intake of yearling steers from nitrogen- (N) fertilized Russian wildrye (Psathyrostachys junceus) pastures was determined by an external indicator technique on five occasions during the summers of 1986 and 1987 at Swift Current, Saskatachewan. The N fertility levels were: 55 kg ha−1 N and 110 kg ha−1 N (the sum of available N and annually applied N fertilizer) and an unfertilized control (15 kg ha−1 available nitrate-N). Forage dry matter intake by steers (290 kg at turn out in May) was 1.5% of steer body weight (BW) when forage dry matter digestibility (DMD) was 48% and averaged 2.3% of steer BW when DMD was 54–62%. Forage dry matter intake was indirectly related to the N fertility level of the pasture by the positive effect of N fertilizer level on forage DMD. Fecal output, as determined by chromic oxide dilution, varied from 0.86% of BW in August 1986 to 1.12% of BW in July 1987. There was no relationship of fecal output to the N fertility of the grazed pasture. Time spent grazing during a 1-d period was determined in each of June, July and August of 1986 and 1987. Grazing time averaged 8.0 h d−1 and was not affected by season or fertility treatment. Forage and fecal contents of acid detergent lignin, ash and N were significantly correlated with the N fertility level of the pasture from which they came. It was concluded that forage intake of animals grazing N-fertilized pastures may be affected indirectly by the effect of soil N fertility on DMD. Key words: Psathyrostachys juncea, fecal output, feces composition, forage digestibility
48
Trigunasih, Ni Made, and Moh Saifulloh. "Correlation Between Soil Nitrogen Content and NDVI Derived from Sentinel-2A Satellite Imagery." Jurnal Lahan Suboptimal : Journal of Suboptimal Lands 11, no. 2 (October 1, 2022): 112–19. http://dx.doi.org/10.36706/jlso.11.2.2022.574.
Full textAbstract:
The United Nations Educational, Scientific, and Cultural Organization (UNESCO) has recognized the Balinese agricultural irrigation system known as subak as part of the world's cultural heritage. Subak is the driver of Bali’s agricultural and tourism sectors and, therefore, must be preserved. Population growth triggers the conversions of land functions, from subak to built-up lands, such as those transpiring in Denpasar City. On the other hand, with the population continuously increasing, the demand for food becomes inevitably higher. This has caused farmers to intensify their agricultural practices through, for instance, applying chemical fertilizers excessively-potentially decreasing soil fertility. An example is urea fertilizer that contains a macronutrient, i.e., nitrogen (N). This study aimed to analyze the soil N content and its correlation with rice growth using the Normalized Difference Vegetation Index (NDVI). The Kjeldahl method was conducted to measure the N levels in the soil laboratory. NDVI was extracted from remote sensing data, namely Sentinel-2A imagery, on a cloud computing platform, Google Earth Engine (GEE), using Band 8 (NIR) with a wavelength of 0.842 m and Band 4 (Red) with 0.665 m. The results showed that the N levels varied from 0.09% to 0.31% and the average NDVI values ranged from 0.47 to 0.54. There is a strong correlation (r = 0.75 to 0.78) between the NDVI values derived from the Sentinel-2A Satellite Imagery and the soil nitrogen content. Spatially, based on the analysis results of the 2019‒2021 data, parts of existing subak systems, i.e., Subak Kerdung, Mergaya, Padanggalak, and Sembung, have high soil N contents and NDVI values.
49
Mondal, Mousumi, Milan Skalicky, Sourav Garai, Akbar Hossain, Sukamal Sarkar, Hirak Banerjee, Rajib Kundu, et al. "Supplementing Nitrogen in Combination with Rhizobium Inoculation and Soil Mulch in Peanut (Arachis hypogaea L.) Production System: Part II. Effect on Phenology, Growth, Yield Attributes, Pod Quality, Profitability and Nitrogen Use Efficiency." Agronomy 10, no. 10 (October 5, 2020): 1513. http://dx.doi.org/10.3390/agronomy10101513.
Full textAbstract:
Peanut (Arachis hypogaea L.) is adorned as the one of the important sources of vegetable oil, protein, vitamins and several minerals, which could mitigate the nutritional gap worldwide. However, peanut cultivation in winter suffers from low temperature stress and knowledge lacuna regarding the optimum dose nitrogen. Therefore, the present investigations were carried out during the winter seasons 2015–2016 and 2016–2017 at the district seed farm of Bidhan Chandra Krishi Viswavidyalaya, an agricultural university in West Bengal, India (23°26’ N, 88°22´ E, elevation 12 m above mean sea level) to facilitate the comprehensive study of plant growth, productivity and profitability of an irrigated peanut crop under varied levels of nitrogen: with and without a rhizobium inoculants and with and without polythene mulch. Quality traits and nutrient dynamics were also itemized. Fertilizing with 100% of the recommended dose of nitrogen combined with rhizobium inoculant and polythene mulch significantly enhanced peanut plant growth, yield and yield-attributing traits, while resulting in the maximum fertilizer (i.e., nitrogen, phosphorus and potassium) uptake by different plant parts. The greatest number of root nodules occurred in the treatment that received 75% of the recommended dose of nitrogen with rhizobium supplementation under polythene mulch, while 50% of the recommended dose of nitrogen with no rhizobium resulted in maximum fertilizer nitrogen use efficiency. Applying the full recommended dose of nitrogen with the rhizobium inoculants and mulch resulted in maximum profitability in the peanut crop.
50
Berkovich, Yu A., S. O. Smolianina, V. G. Smolianin, Ya V. Morozov, and I. G. Tarakanov. "TECHNOLOGY OF MINERAL NUTRITION AND ILLUMINATION OF CROPS IN A SPACE VEGETABLE GREENHOUSE." Aerospace and Environmental Medicine 55, no. 6 (2021): 68–74. http://dx.doi.org/10.21687/0233-528x-2021-55-6-68-74.
Full textAbstract:
Dependence of Chinese cabbage productivity and nitrate content in eatable biomass on the ammonium and nitrate nitrogen ratio and red light fraction was studied in the context of space greenhouse Vitacycle-T design. Crops were illuminated by a lighting unit assembled of red and white light-emitting diodes (LEDs) producing the photosynthetic photon flux (PPF) of 400–430 µmol/(m2•с) with the ratio of red and white LEDs inputs between 0 and 1.5. The ammonium-nitrate nitrogen ratio in nutrient solutions with stabilized total nitrogen varied from 0 to 1. Under all tested light spectra the favorable range of ammonium nitrogen makes up 15 to 45 mg/L with the maximum of 25 ± 2 mg/L and total nitrogen at 120 mg/L. Ammonium nitrogen increase above 53–55 mg/L leads to crop inhibition. Concentration of nitrates in eatable biomass did not exceed the permissible levels established for leave vegetables irrespectively of the ammonium-nitrate nitrogen ratio and decreased monotonously as ammonium nitrogen was rising above 10 mg/L. According to calculation, the Vitacycle-T root-feeding design (cartages of granular mineral-rich ionite BIONA-312 and slow-release fertilizer Osmocote 14-14-14) is capable to control total nitrogen and ammonium-nitrate nitrogen ratio within the favorable range.