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Thematische Bibliographien / Crops and nitrogen / Zeitschriftenartikel

Zeitschriftenartikel zum Thema „Crops and nitrogen“

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Autor: Grafiati

Veröffentlicht am 4. Juni 2021

Zuletzt aktualisiert am 31. Januar 2023

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1

KUMAR, YOGENDRA. „Nanofertilizers for enhancing nutrient use efficiency, crop productivity and economic returns in winter season crops of Rajasthan“. Annals of Plant and Soil Research 22, Nr. 4 (04.11.2020): 324–35. http://dx.doi.org/10.47815/apsr.2020.10001.

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The results of 600 on-farm trials with 8 crops conducted during winter season in different districts of Rajasthan have proved that the quantity of urea being applied by the farmers to supply nitrogen to the crops can be successfully reduced to half. The yields obtained with 50% less nitrogen plus 2 sprays of nano-nitrogen in standing crops gave yields higher than that applied in most of the 8 crops tested in these trials. Apart from this, effect of the Nano-Zn and Nano-Cu was also evaluated. As the deficiencies of these micronutrients were not universal like nitrogen, the significant responses to these nanofertilizers depended on the magnitude of deficiency of specific micronutrients and the nature of the crops.These results clearly establish that with application of nanofertilizers, the nutrient use efficiency can be significantly enhanced as revealed by 50 per cent saving of urea through 2 sprays of Nano N.Nanofertilizers are considered as a novel approach towards saving of nutrients, in particular nitrogen, and protecting the environment.This paper describes the results of 600 on-farm trials conducted on 8 crops grown during winter season of 2019-20.

2

Yamagata, Makoto, und Noriharu Ae. „Nitrogen uptake response of crops to organic nitrogen“. Soil Science and Plant Nutrition 42, Nr. 2 (01.06.1996): 389–94. http://dx.doi.org/10.1080/00380768.1996.10415110.

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3

Kubát, J., J. Klír und D. Pova. „The dry nitrogen yields nitrogen uptake, and the efficacy on nitrogen fertilisation in long-term experiment in Prague“. Plant, Soil and Environment 49, No. 8 (10.12.2011): 337–45. http://dx.doi.org/10.17221/4134-pse.

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Long-term field experiments conducted under different soil and climate conditions and their databases provide invaluable information and are indispensable means in the study of the productivity and sustainability of the soil management systems. We evaluated the results of the dry matter yields of the main products obtained with four variants of organic and mineral fertilisation in three long-term field experiments established in 1955. The experiments differed in the cultivated crops. The period of evaluation was 12 and 16 years (1985–2000), respectively. The productivity of nine-year crop rotation was lower with the fertilised variants than that with the alternative growing of spring wheat and sugar beets. The dry matter yields on the Nil variants, however, were higher in the crop rotation than in the alternate sugar beet and spring wheat growing, apparently due to the symbiotic nitrogen fixation. The dry matter yields of sugar beet and mainly of spring wheat declined in almost all variants of fertilisation in the alternate sugar beet and spring wheat growing, over the evaluated time period. In spite of the relatively high dry matter production, the declining yields indicated a lower sustainability of the alternate cropping system. Both organic and mineral fertilisation increased the production of the cultivated crops. The differences in the average dry matter yields were statistically significant. Both organic and mineral fertilisation enhanced significantly the N-uptake by the cultivated crops. The effectivity of nitrogen input was the highest with the alternate cropping of sugar beet and spring wheat indicating that it was more demanding for the external N-input and thus less sustainable than nine-year crop rotation.

4

Tkachuk, Oleksander, und Vitalii Ovcharuk. „ECOLOGICAL POTENTIAL OF GRAIN PEGULUM CROPS IN MODERN INTENSIVE CROP ROTATIONS“. Agriculture and Forestry, Nr. 3 (30.10.2020): 161–71. http://dx.doi.org/10.37128/2707-5826-2020-3-14.

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The article discusses the ecological significance of leguminous crops grown in modern intensive crop rotation. In particular, the area under crops of common leguminous crops in Ukraine and the level of their productivity have been analyzed. A comparison is made with the acreage of the most widespread grain crops. The emphasis of the article is aimed at establishing the level of nitrogen fixation of leguminous crops, which have the largest sown areas in Ukraine. The volume of accumulation by these leguminous crops of by-products in the form of their straw and stubble is also calculated. A comparison is made according to these indicators with the most widespread grain crops grown in Ukraine. The data on the content of the main nutrients in the by-products of leguminous crops - nitrogen, phosphorus, potassium are given. On the basis of these indicators, a calculation was made of the accumulation of the main nutrients in the soil, which can come with the by-products of leguminous crops with an average yield of their seeds. We also compared the obtained indicators with the input of nitrogen, phosphorus and potassium into the soil with by-products of the most common grain crops. Based on this, a conclusion was made about the most effective leguminous crops, the cultivation of which in the modern intensive crop rotation contributes most to the stabilization of the agro-ecological state of the soil. According to the State Statistics Service in Ukraine in 2019, the largest sown area among leguminous crops belonged to peas - 347.0 thousand hectares, which is 61.3% in the structure of all leguminous crops. In total, the sown area for leguminous crops in Ukraine is 566.0 thousand hectares, which is about 2% of the total sown area and this is a very low indicator. Considering the average yield in Ukraine, beans can return more by-products to the soil - 3.5 t/ha, soybeans and peas - by 8.6% less, beans - by 37.1%, and least of all - chickpeas and lentils - 1.7 - 1.8 t/ha. The content of the main macronutrients in the by-products of all leguminous crops is similar and is: nitrogen - 10.0-12.0 kg/t, phosphorus - 3.4-3.6 kg/t, potassium - 4.6-5.0 kg/t. It has been proven that an increase in the area of leguminous crops in an intensive crop rotation will have a positive effect on the agro-ecological state of the soil. In particular, growing beans allows you to get the highest mass of by-products that can be ploughed into the soil - 3.5 t/ha. Also, by-products of beans are characterized by a high content of mineral phosphorus - 3.6 kg/t, which ensures the supply of all mineral phosphorus to the soil - 12.6 kg/ha of all leguminous crops, as well as potassium - 16.5 kg/ha. Soybean by-products are characterized by a high nitrogen content - 12.0 kg/t, phosphorus - 3.6 kg/t and potassium - 5.0 kg/t. This allows, after growing soybeans, to accumulate in the soil with by-products more mineral nitrogen - 38.4 kg/ha. Also, soybeans are characterized by a high symbiotic nitrogen-fixing ability among all leguminous crops - 120 kg/ha. By-products of leguminous crops have a high content of nitrogen - 2.3-2.7 times, phosphorus - 1.5-1.6 times compared to by-products of grain crops. Also, when plowing soybean by-products into the soil, there will be 2 times more mineral nitrogen and 1.1-1.3 times more phosphorus than when plowing winter wheat by-products. Key words: egumes, by-products, nitrogen fixation, nutrients, accumulation, soil.

5

Tei, Francesco, Stefaan De Neve, Janjo de Haan und Hanne Lakkenborg Kristensen. „Nitrogen management of vegetable crops“. Agricultural Water Management 240 (Oktober 2020): 106316. http://dx.doi.org/10.1016/j.agwat.2020.106316.

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6

Jensen, Erik Steen. „Nitrogen Accumulation and Residual Effects of Nitrogen Catch Crops“. Acta Agriculturae Scandinavica 41, Nr. 4 (Januar 1991): 333–44. http://dx.doi.org/10.1080/00015129109439917.

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7

Thorup-Kristensen, K. „The effect of nitrogen catch crop species on the nitrogen nutrition of succeeding crops“. Fertilizer Research 37, Nr. 3 (1994): 227–34. http://dx.doi.org/10.1007/bf00748941.

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8

Gaskell, Mark, und Richard Smith. „Nitrogen Sources for Organic Vegetable Crops“. HortTechnology 17, Nr. 4 (Januar 2007): 431–41. http://dx.doi.org/10.21273/horttech.17.4.431.

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Fertilization is the most expensive cultural practice for the increasing numbers of organic vegetable growers in the United States. Nitrogen (N) is the most important and costly nutrient to manage, and cost-effective N management practices are needed for efficient organic vegetable production. There is a wide array of organic N sources available, but they vary in cost, N content, and N availability. Compost and cover crops are commonly used sources of N for vegetables because they are relatively inexpensive and offer additional nutrients or soil improvement qualities in addition to N. Studies have shown that compost quality factors that affect N mineralization vary by source and among different batches from the same source. Compost carbon to N ratio should be equal to or less than 20:1 to assure net short-term mineralization. Cover crops also vary in N content and mineralization rate after incorporation. Leguminous cover crops decompose and release N more rapidly than grass or cereal cover crops at the preheading stage typically incorporated. Even the most efficient N-supplying composts, cover crops, or other organic N sources do not release appreciable N to a subsequent crop beyond 6 to 8 weeks from incorporation, and this burst of early N may not synchronize with N requirements for many vegetable crops. Other potential organic fertilizer N sources have been evaluated for vegetables, and they vary in N cost and N mineralization rate. Materials evaluated include seabird guano, liquid fish, feather meal, corn meal (Zea mays), blood meal, and liquid soybean meal (Glycine max) among others. Of those evaluated, feather meal, seabird guano, and liquid fish stand out as more economical organic sources of available N. Organic sources generally lack uniformity and are bulky, unstable, and inconsistent as a group, and this contributes to additional hidden management costs for organic growers. Liquid organic N sources for use in microirrigation systems may have additional disadvantages caused by loss of valuable nutrient N that is removed by filters.

9

Colaço, A. F., und R. G. V. Bramley. „Do crop sensors promote improved nitrogen management in grain crops?“ Field Crops Research 218 (April 2018): 126–40. http://dx.doi.org/10.1016/j.fcr.2018.01.007.

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10

Balbinot Junior, Alvadi Antonio, Milton da Veiga, Anibal de Moraes, Adelino Pelissari, Álvaro Luiz Mafra und Cristiano Dela Piccolla. „Winter pasture and cover crops and their effects on soil and summer grain crops“. Pesquisa Agropecuária Brasileira 46, Nr. 10 (Oktober 2011): 1357–63. http://dx.doi.org/10.1590/s0100-204x2011001000032.

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The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N) fertilization (intercropping cover); the same intercropping, with grazing and 100 kg ha-1 of N per year topdressing (pasture with N); the same intercropping, with grazing and without nitrogen fertilization (pasture without N); oilseed radish, without grazing and nitrogen fertilization (oilseed radish); and natural vegetation, without grazing and nitrogen fertilization (fallow). Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.

11

Batal, K. M., D. R. Decoteau, J. T. Garrett, D. M. Granberry, D. C. Sanders, J. M. Davis, G. D. Hoyt und R. J. Dufault. „CROP YIELD AND BIOMASS AS CORRELATED WITH N LEVELS AND COVER CROPS“. HortScience 31, Nr. 5 (September 1996): 748f—749. http://dx.doi.org/10.21273/hortsci.31.5.748f.

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Cucumber and potato crops were tested in a rotation with winter cover crops at different locations in Georgia, North Carolina, and South Carolina from 1991 to 1994. Biomass DM of vegetable crops was greatest when grown after crimson clover. Clover plantings resulted in a greater biomass than wheat when preceded spring cucumber crop. Vegetable biomass produced on clover plots or with N rates of 60 to 120 kg·ha–l was equivalent. Nitrogen recovery by cover and vegetable crops was enhanced by clover plantings. Clover biomass (tops only) provided an average of 138 kg N/ha for the cucumber crop, compared to an average of 64 kg N/ha provided by wheat. Nitrogen recovery by vegetable crops was also enhanced with 60–120 kg N/ha rates. Yields were highest when high N rates were used and when crops were produced on clover plots. Vegetable yield, cover crop biomass, and N recovery were positively correlated with vegetable biomass and applied N.

12

Thilakarathna, Malinda S., Stephanie Serran, John Lauzon, Ken Janovicek und Bill Deen. „Management of Manure Nitrogen Using Cover Crops“. Agronomy Journal 107, Nr. 4 (Juli 2015): 1595–607. http://dx.doi.org/10.2134/agronj14.0634.

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13

Paparozzi, Ellen T. „NITROGEN AND SULFUR INTERACTION IN FLORICULTURAL CROPS“. Acta Horticulturae, Nr. 481 (Januar 1999): 379–84. http://dx.doi.org/10.17660/actahortic.1999.481.44.

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14

Yan, Ming, Genxing Pan, Jocelyn M. Lavallee und Richard T. Conant. „Rethinking sources of nitrogen to cereal crops“. Global Change Biology 26, Nr. 1 (02.12.2019): 191–99. http://dx.doi.org/10.1111/gcb.14908.

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15

Bot, Jacques Le, und Stéphane Adamowicz. „Nitrogen Nutrition and Use in Horticultural Crops“. Journal of Crop Improvement 15, Nr. 2 (16.06.2006): 323–67. http://dx.doi.org/10.1300/j411v15n02_10.

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16

Echeverría, H. E., C. A. Navarro und F. H. Andrade. „Nitrogen nutrition of wheat following different crops“. Journal of Agricultural Science 118, Nr. 2 (April 1992): 157–63. http://dx.doi.org/10.1017/s0021859600068738.

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SUMMARYA trial using a split-plot with blocks design was carried out at the INTA Balcarce Experimental Station, Argentina on a typic argiudol soil to evaluate N nutrition in wheat after different preceding crops and using two rates of N fertilization (0 and 90 kg N/ha).Wheat (Triticum aestivum), soyabean (Glycine max), sunflower (Helianthus annuus) and maize (Zea mays) were grown in different combinations for two successive years (1984/85 and 1985/86).No water stress was detected during either growing season. Nitrogen availability was altered by the previous crops grown, but the effect lasted only for one season. Wheat following maize yielded least with no N and responded most to N fertilization. The highest yields of wheat without N and the lowest response by wheat to N fertilization were found after crops of soyabean and sunflower.Wheat after a fertilized wheat crop did not respond to N fertilization because of a serious attack of take-all (Gaeumannomyces graminis tritici).The nitrate concentration in wheat stem bases was found to be a good estimator of the availability of soil N.

17

Keulen, H., und W. Stol. „Quantitative aspects of nitrogen nutrition in crops“. Fertilizer Research 27, Nr. 2-3 (März 1991): 151–60. http://dx.doi.org/10.1007/bf01051123.

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18

Rahn, C. R. „NITROGEN AND FIELD PRODUCTION OF VEGETABLE CROPS“. Acta Horticulturae, Nr. 533 (Juni 2000): 361–70. http://dx.doi.org/10.17660/actahortic.2000.533.44.

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19

Sørensen, Jørn Nygaard, und Kristian Thorup-Kristensen. „Nitrogen effects of non-legume catch crops“. Zeitschrift für Pflanzenernährung und Bodenkunde 156, Nr. 1 (1993): 55–59. http://dx.doi.org/10.1002/jpln.19931560109.

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20

Nakhone, Lenah N., und M. Ali Tabatabai. „Nitrogen mineralization of leguminous crops in soils“. Journal of Plant Nutrition and Soil Science 171, Nr. 2 (April 2008): 231–41. http://dx.doi.org/10.1002/jpln.200625162.

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21

Heege, Hermann J., und Stefan Reusch. „Nitrogen and the Colour of the Crops“. German Research 24, Nr. 2-3 (Dezember 2002): 8–10. http://dx.doi.org/10.1002/germ.200290015.

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22

Eck, H. V., und O. R. Jones. „Soil Nitrogen Status as Affected by Tillage, Crops, and Crop Sequences“. Agronomy Journal 84, Nr. 4 (Juli 1992): 660–68. http://dx.doi.org/10.2134/agronj1992.00021962008400040025x.

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23

ȘIMON, Alina, Adrian CECLAN, Florin RUSSU, Marius BĂRDAȘ, Felicia CHEȚAN und Alin POPA. „INFLUENCE OF NP MINERAL FERTILIZATION ON SOYBEAN CROPS“. LIFE SCIENCE AND SUSTAINABLE DEVELOPMENT 3, Nr. 1 (29.07.2022): 84–90. http://dx.doi.org/10.58509/lssd.v3i1.171.

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Soybean is one of the most important sources of vegetable protein, having a great agronomic importance by fixing atmospheric nitrogen following symbiosis with bacteria of the genus Rhizobium. Bifactorial experience, of the AxB model A - phosphorus doses: P0; P40; P80; P120; P16 and B - nitrogen doses:N0; N25; N50; N75; N100, aims to identify the influence of these doses on the development of soybean cultivation. Although soybeans are a heavy consumer of nitrogen and phosphorus in the early stages of development, however, they do not react well to large amounts of nitrogen as they prevent the development of the number of nodules on soybean roots and inhibits the growth of bacteria, and the increases obtained production do not justify the higher amount of nitrogen applied to soybeans. The number of pods and the mass of 1000 grains are also influenced more by the application of phosphorus doses than nitrogen. Phosphorus applied in higher amounts leads to an increase of over 60% of the number of nodules but also at significant production increases of 5-7%, compared to the non-fertilized variant. On nutrient-rich soils, soybeans do not require fertilization with large amounts of nitrogen, but they react very well to the application of phosphorus fertilizers.

24

Mangan, Francis X., und Stephen J. Herbert. „WINTER-KILLED LEGUMINOUS COVER CROPS FOR SWEET CORN“. HortScience 27, Nr. 11 (November 1992): 1161f—1161. http://dx.doi.org/10.21273/hortsci.27.11.1161f.

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Field research was conducted in Deerfield, Mass. to study the effects of leguminous cover crops on sweet corn yield. Oat was planted alone and in combination with four leguminous cover crops August 8, 1990. Cover crop residue was disked once and sweet corn seeded April 23, 1991. Each cover crop combination had three rates of nitrogen added in two applications. Sweet corn seeded into stands of hairy vetch (Vicia villosa) yielded the highest of the cover crop combinations. All leguminous cover crop treatments yielded higher than oat alone or no cover crop when no synthetic nitrogen was added. Cover crop combinations were seeded again in the same field plots August 12, 1991. Oat biomass in November was greater where there had been leguminous cover crops or high rates of synthetic nitrogen. Legume growth was retarded in the plots that had previously received high nitrogen. It is thought that legume growth was reduced in the high nitrogen treatments due to increased oat growth and higher soil nitrogen levels which could inhibit root nodulation.

25

Iduna, Arduini, Cardelli Roberto und Pana Silvia. „Biosolids affect the growth, nitrogen accumulation and nitrogen leaching of barley“. Plant, Soil and Environment 64, No. 3 (21.03.2018): 95–101. http://dx.doi.org/10.17221/745/2017-pse.

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Biosolids are organic fertilisers derived from treated and stabilised sewage sludge that increase soil fertility and supply nitrogen to crops over a long period, but can also increase the risk of nitrogen (N) leaching. In this work, spring barley was grown in lysimeters filled with soil amended with biosolids, and with and without mineral N fertilisation. Biomass and the N concentration and content of shoots and roots were determined at flowering and maturity, and the N remobilization was calculated during grain filling. Drainage water was collected and analysed for N leaching. Biosolids increased soil porosity and soil nitrate, and positively affected the growth and N uptake of barley. Compared to mineral fertilisers, biosolids produced 18% higher vegetative biomass and 40% higher grain yield. During grain filling, both N uptake and N remobilization were higher with biosolids, which increased the grain N content by 32%. Nitrogen loss in leachates was 1.2% of plant uptake with mineral fertilisers and 1.7% with biosolids. Thus, soil fertilisation with biosolids greatly benefits spring barley, only slightly increasing N leaching.

26

Haynes, R. J., R. J. Martin und K. M. Goh. „Nitrogen fixation, accumulation of soil nitrogen and nitrogen balance for some field-grown legume crops“. Field Crops Research 35, Nr. 2 (November 1993): 85–92. http://dx.doi.org/10.1016/0378-4290(93)90141-9.

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27

Lupwayi, Newton Z., und Yoong K. Soon. „Nitrogen-Related Rotational Effects of Legume Crops on Three Consecutive Subsequent Crops“. Soil Science Society of America Journal 80, Nr. 2 (März 2016): 306–16. http://dx.doi.org/10.2136/sssaj2015.08.0299.

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28

Blanco-Canqui, Humberto, M. M. Claassen und D. R. Presley. „Summer Cover Crops Fix Nitrogen, Increase Crop Yield, and Improve Soil-Crop Relationships“. Agronomy Journal 104, Nr. 1 (Januar 2012): 137–47. http://dx.doi.org/10.2134/agronj2011.0240.

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29

Colangelo, David J., und Mark H. Brand. „Water and Nitrogen Management to Reduce Nitrate-Nitrogen Leaching from Container Crops“. HortScience 32, Nr. 3 (Juni 1997): 455E—455. http://dx.doi.org/10.21273/hortsci.32.3.455e.

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Plastic 208-L industrial barrels (14 total) were modified for use as soil-filled lysimeters to study the nitrogen dynamics of a typical container crop production system. The top of each barrel was removed and the bottom was fitted with a drain hole and filter fabric. The drain was then connected via tubing to a 2-L leachate collection vessel made from a length of 15.24-cm-diameter PVC pipe that had been capped on one end. All barrels and connected collection vessels were recessed into a grassed slope. Barrels were filled with homogeneous B and C horizon soil to simulate soil conditions of a typical container nursery. Uniform Rhododendron `Catawbiense Album' plants in 4.5-L containers were arranged atop the barrellysimeters at four plants per barrel. Irrigation/fertilizer treatments included fertilized pulse trickle irrigation (four replications), fertilized overhead irrigation (four replications), and unfertilized controls corresponding to each irrigation treatment (three replications each). All fertilized plants received 10 g of 17N–6P–10K 8- to 9-month controlled-release fertilizer at the beginning of the crop cycle. Leachate from the barrel-lysimeters was collected weekly and total volume, total Kjeldahl N, nitrate-N, and ammonium-N were determined. Peak nitrate-N levels were well above the current drinking water standard for both irrigation treatments at certain times during the year. Cumulative nitrate-N mass output was similar for both irrigation treatments. A nitrogen balance for the complete production system including fertilizer and irrigation water input, plant material, potting media, soil in the lysimeter barrels and leachate output from the barrels has also been determined.

30

Stevenson, F. C., und C. van Kessel. „The nitrogen and non-nitrogen rotation benefits of pea to succeeding crops“. Canadian Journal of Plant Science 76, Nr. 4 (01.10.1996): 735–45. http://dx.doi.org/10.4141/cjps96-126.

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The inclusion of a pulse crop in a rotation often leads to greater seed yields in the succeeding cereal crop. Two rotations were established at three sites in 1993 to examine the N and non-N rotation benefits of pea (Pisum sativum L.) to the subsequent wheat (Triticum aestivum L.) then oilseed crops. Wheat seed yield was 43% greater (rotation benefit) when preceded by pea rather than wheat, a consistent response among sites. Six to fourteen kg ha−1 of the extra 27 kg ha−1 of N accumulated by wheat in the pea–wheat rotation was derived from the additional N derived from pea residue. The additional soil N availability in the pea–wheat rotation, as indicated by the A-value, explained 8% of the rotation effect on seed yield (N benefit). The remaining 92% of the yield advantage in the pea–wheat rotation was attributed to non-N rotation benefit. The yield of the oilseed crop following the pea–wheat phase of the rotation did not differ from that following the wheat–wheat phase. The influence of growing conditions and cropping history on the magnitude of the N to non-N rotation benefits, and the contribution of different non-N effects, should be investigated further. Key words: Rotation benefit, pea, wheat, residue N, non-N benefit

31

PADHAN, BIRENDRA KUMAR, LEKSHMY SATHEE und VANITA JAIN. „Nitrogen remobilization and its importance in nitrogen use efficiency (NUE) of crops“. Indian Journal of Agricultural Sciences 90, Nr. 12 (10.02.2021): 2251–61. http://dx.doi.org/10.56093/ijas.v90i12.110299.

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Nitrogen (N) remobilization during grain filling from pre-anthesis N uptake and stored in different tissues of crop N use efficiency (NUE). N is remobilized from to sink (young leaves or grains) with the help of nitrate/amino acid transporters. Nearly 80% of grain N in cereals is derived from N remobilized from vegetative tissues. Remobilization of N within the plant takes place from older leaves to young leaves, leaves to grains, senescing organs to grains, from storage parts to grains. Enzymes involved in N remobilization include glutamine synthetase (GS), glutamate dehydrogenase (GDH), asparagine synthetase (AS) and proteases. Among them, cytosolic GS plays a key role during N remobilization in cereals. There are various senescence-associated genes (SAG) involved in N remobilization from older degrading leaves to younger leaves and grains. Autophagy (ATG) is an important mechanism involved in the degradation of stored N in the form of various proteins to amino acids, which are transported to long-distance in the form of glutamine and asparagine via phloem tissue. There is a complex network of genes, mechanisms, and factors associated with N remobilization, which needs to be considered for improving NUE of crops.

32

Козырева, М. Ю., und Л. Ж. Басиева. „THE NITROGEN CONSUMPTION BY ALFALFA CROPS DEPENDING ON THE NITROGEN NUTRITION PATTERN“. Niva Povolzh`ia, Nr. 3(56) (17.12.2020): 50–56. http://dx.doi.org/10.36461/np.2020.56.3.015.

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Приведены результаты полевых исследований потребления азота посевами люцерны в зависимости от режима азотного питания и симбиотической активности посевов за 2017…2019 годы. Опыты с люцерной синегибридной проведены в экологических условиях предгорной зоны РСО-Алания на черноземе выщелоченном с близким залеганием галечника. Сравнивались минеральный и симбиотрофный режимы азотного питания растений люцерны. Установлено, что в год посева потребление азота посевами люцерны составило от 105,0 до 135,4 кг/га, при этом к первому укосу потребление было в 1,1…1,2 раза больше, чем ко второму укосу. На второй и третий годы пользования посевами потребление азота выросло в 1,7…1,9 раза в сравнении с показателями года посева. Показатели вариантов с естественными условиями (контроль) и внесением стартовых доз азотных удобрений (N30) были практически идентичными. Показатели вариантов с инокуляцией семян высокогорным инокулюмом (Ин-1800) и внесением стартовых доз азотных удобрений на фоне инокуляции (N30 + Ин) во второй и третий годы пользования посевами были практически идентичными. Объемы потребления азота в указанных вариантах составили свыше 235 кг/га, или на 25,6…27,1 % выше показателей контрольного варианта. В сумме за три года исследований посевы люцерны в контрольном варианте усвоили 483,3 кг/га азота. Стартовые дозы азотных удобрений (N30) увеличили данный показатель всего на 1,4 %. Предпосевная инокуляция семян способствовала увеличению потребления азота во всех вариантах: в варианте с промышленным штаммом ризоторфина (Шт. 425а) – на 17,8 %, с высокогорным инокулюмом на фоне внесения стартовых доз минеральных азотных удобрений (N30 + Ин) – на 24,6 %, с высокогорным инокулюмом в чистом виде (Ин-1800) – на 27,1 %. Ключевые слова: люцерна, режим питания, симбиотическая активность, минеральный азот, биологический азот, потребление азота. The results of field studies of nitrogen consumption in alfalfa crops depending on the nitrogen nutrition pattern and symbiotic activity of crops for 2017...2019 are presented. Experiments with the alfalfa purple were carried out in the ecological conditions of the foothill zone of the North Ossetia-Alania, on leached chernozem with a close occurrence of gravel. Mineral and symbiotrophic patterns of nitrogen nutrition of alfalfa plants were compared. It was found that in the year of planting, the nitrogen consumption of alfalfa crops ranged from 105.0 to 135.4 kg/ha, and by the first mowing, the consumption was 1.1...1.2 times bigger than by the second mowing. In the second and third years of crop use, nitrogen consumption increased by 1.7...1.9 times compared to the year of planting. The parameters of the options with natural conditions (control) and the addition of starting doses of nitrogen fertilizers (N30) were almost identical. In the second and third years of use of crops, parameters of options with inoculation of seeds with high-altitude inoculum (In-1800) and the addition of starting doses of nitrogen fertilizers within the background of inoculation (N30 + in) were almost identical. In these options, the amount of nitrogen consumption was more than 235 kg/ha, or 25.6...27.1 % higher than in the control variant. In total, over three years of research, in the control option alfalfa crops took 483.3 kg/ha of nitrogen. Starting doses of nitrogen fertilizers (N30) increased this indicator by only 1.4 %. Pre-planting inoculation of seeds contributed to an increase in nitrogen consumption in all options: in the option with the industrial strain of risotorphine (St. 425a) – by 17.8 %, with high-altitude inoculum within the background of adding starting doses of mineral nitrogen fertilizers (N30 + In) – by 24.6 %, with high-altitude inoculum in pure form (In-1800) – by 27.1 %.

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Padilla, Francisco M., Michela Farneselli, Giorgio Gianquinto, Francesco Tei und Rodney B. Thompson. „Monitoring nitrogen status of vegetable crops and soils for optimal nitrogen management“. Agricultural Water Management 241 (November 2020): 106356. http://dx.doi.org/10.1016/j.agwat.2020.106356.

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Volkohon, V. V., S. B. Dimova, K. I. Volkohon, L. M. Tokmakova, M. A. Zhurba, Y. M. Halep, N. P. Shtanko und N. V. Lutsenko. „BIOLOGICAL ASPECTS OF CROPS FERTILIZING SYSTEMS“. Agriciltural microbiology 22 (29.12.2015): 13–29. http://dx.doi.org/10.35868/1997-3004.22.13-29.

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The process of nitrogen fixation and N2O emission in the system “soil – plant” was studied in the conditions of field stationary experiment on leached black soil when growing crops in short rotation crop succession (potato – barley – peas – winter wheat) in case of different fertilization systems and application of microbial agents. Using directivity indexes of processes of nitrogen biological transformation in agrocoenosis and economic calculations an environmental and economic rationale for fertilization was composed.

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Hellebrand, H. J., V. Scholz und J. Kern. „Nitrogen conversion and nitrous oxide hot spots in energy crop cultivation“. Research in Agricultural Engineering 54, No. 2 (24.06.2008): 58–67. http://dx.doi.org/10.17221/1001-rae.

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Since 1999, nitrous oxide (N<sub>2</sub>O) soil emissions from sites cultivated with energy plants have been measured by gas chromatography and gas flux chambers in experimental fields. The main aim of this study was the nitrogen conversion factor and its variability for sandy soils under climatic conditions of Central Europe. Annual plants (hemp, rape, rye, sorghum, triticale) and perennial plants (grass, perennial rye, poplar, willow) were fertilised with three different levels of nitrogen (150 kg N/ha/year, 75 kg N/ha/year, and none). The annual nitrogen conversion factors were derived from the annual mean differences between the fertilised sites and non-fertilised control sites. The mean nitrogen conversion factor for the non-cultivated soils was lower (perennial crops: 0.4%) than that for the regularly cultivated soils (annual crops: 0.9%). Few times, enhanced N<sub>2</sub>O emission spots with maxima above 1000 μ<sub>2</sub>O/m<sup>2</sup>/h, lasting for several weeks, were observed in the course of measurements. The influence of these local peak emissions on the nitrogen conversion factor is discussed.

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Cocking, Edward, und David Dent. „The prospect of N2-fixing crops galore!“ Biochemist 41, Nr. 4 (01.08.2019): 14–17. http://dx.doi.org/10.1042/bio04104014.

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The impact of carbon on our climate has been of major concern for a number of years. However, we are now learning to be equally concerned about the next element in the periodic table, nitrogen, and the consequences of using synthetic nitrogen fertilizers in agriculture that pollute our planet and its atmosphere.

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Sainju, Upendra M., Bharat P. Singh, Wayne F. Whitehead und Shirley Wang. „Accumulation and Crop Uptake of Soil Mineral Nitrogen as Influenced by Tillage, Cover Crops, and Nitrogen Fertilization“. Agronomy Journal 99, Nr. 3 (Mai 2007): 682–91. http://dx.doi.org/10.2134/agronj2006.0177.

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Goffart, Jean-Pierre, Marguerite Olivier und Marc Frankinet. „Crop Nitrogen Status Assessment Tools in a Decision Support System for Nitrogen Fertilization Management of Potato Crops“. HortTechnology 21, Nr. 3 (Juni 2011): 282–86. http://dx.doi.org/10.21273/horttech.21.3.282.

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A decision support system (DSS) was based on the splitting of total nitrogen (N) fertilizer application combined with in-season assessments of crop N requirements aimed to matching, at field scale, potato (Solanum tuberosum) total crop N requirements and mineral N supply from soil and fertilizers. After the preplanting establishment of the total N recommendation based on the predictive balance-sheet method at a specific field scale, 70% of the recommended amount was applied to the crop at planting. Subsequently, at 20–50 days after emergence (DAE) the need for supplemental N was assessed through noninvasive measurements of leaf chlorophyll concentration directly in the field. A simple conditional relationship was established to support potato growers’ decisions on the usefulness of applying the remaining 30% N. This required a crop N status (CNS) assessment in the fertilized field and within a small, untreated area (zero-N for reference). The strategy developed is economically feasible, easy to operate, and validated for several potato varieties. It also gives the grower the possibility of improving N use efficiency (NUE). Several tools to assess CNS have been investigated, or are currently being investigated, at the Walloon Agricultural Research Center in Gembloux, Belgium (CRA-W) for integration into this strategy. All the tools are evaluated for four main characteristics: measurement accuracy and precision, sensitivity to N, specificity to N, and feasibility. There are invasive or noninvasive tools. The use of a chlorophyll meter (CM) has been currently developed in the DSS. Current CRA-W research is investigating the potential of crop light reflectance as an indicator of CNS (ground-based radiometers for near remote sensing and satellite multispectral imagery for spatial remote sensing).

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Silva, Edson Cabral da, Takashi Muraoka, Alefe Viana Souza Bastos, Vinícius Ide Franzini, Alinne da Silva, Salatiér Buzetti, Karuppan Sakadevan et al. „Nitrogen recovery from fertilizers and cover crops by maize crop under no-tillage system“. MAY 2020, Nr. 14(05):2020 (20.05.2020): 766–74. http://dx.doi.org/10.21475/ajcs.20.14.05.p2127.

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Crop rotation associated with the use of cover crops promotes the introduction of crop residues to the soil, with direct and indirect effects on the availability of plant nutrients, especially nitrogen (N). The objectives of this study were to estimate the N utilization from 15N-urea and cover crop residues (labelled with 15N) of maize crops grown in succession, and evaluate the effects of the isolated and combined use of cover crops and urea on maize plant height, yield components, and grain yield, grown under a no-tillage system. Field research was conducted in an Oxisol (Rhodic Haplustox), Cerrado (Savannah) phase. The experimental design was a randomized block with 20 treatments and four replications in a 5x4 factorial scheme. The treatments were four cover crops species: sunn hemp (Crotalaria juncea L.), pigeon pea (Cajanus cajan (L.) Millsp), green velvet bean (Mucuna prurens), and millet (Pennisetum glaucum L.) + spontaneous vegetation (fallow in the off-season), combined with four N rates: 0, 30, 90, and 150 kg ha-1, applied at the sowing and topdressing stages. The results showed that legume cover crops provided maize grain yields equivalent to the application of 80-108 kg ha-1 N as urea. The urea N utilization by the maize was at an average of 43.5 % of the applied amount. The results indicate that cover crops, particularly legume cover crops, are an important source of N to non-legume cereals. Legumes used as cover crops can replace nitrogen fertilizers of more than 80 kg ha, which is both environmentally and economically viable for corn production.

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Liu, Xiaoli, Qiuwen Chen und Zhaoxia Zeng. „Study on nitrogen load reduction efficiency of agricultural conservation management in a small agricultural watershed“. Water Science and Technology 69, Nr. 8 (11.02.2014): 1689–96. http://dx.doi.org/10.2166/wst.2014.076.

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Different crops can generate different non-point source (NPS) loads because of their spatial topography heterogeneity and variable fertilization application rates. The objective of this study was to assess nitrogen NPS load reduction efficiency by spatially adjusting crop plantings as an agricultural conservation management (ACM) measure in a typical small agricultural watershed in the black soil region in northeast China. The assessment was undertaken using the Soil and Water Assessment Tool (SWAT). Results showed that lowland crops produce higher nitrogen NPS loads than those in highlands. It was also found that corn gave a comparatively larger NPS load than soybeans due to its larger fertilization demand. The ACM assessed was the conversion of lowland corn crops into soybean crops and highland soybean crops into corn crops. The verified SWAT model was used to evaluate the impact of the ACM action on nitrogen loads. The results revealed that the ACM could reduce NO3-N and total nitrogen loads by 9.5 and 10.7%, respectively, without changing the area of crops. Spatially optimized regulation of crop planting according to fertilizer demand and geological landscapes can effectively decrease NPS nitrogen exports from agricultural watersheds.

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Papendick, Robert I., Lloyd F. Elliott und James F. Power. „Alternative production systems to reduce nitrates in ground water“. American Journal of Alternative Agriculture 2, Nr. 1 (1987): 19–24. http://dx.doi.org/10.1017/s0889189300001442.

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AbstractEvidence indicates a strong positive relationship between increases in nitrogen fertilizer use on cropland and nitrate concentrations in shallow ground water. This raises concern about the fate and efficiency of nitrogen fertilizer with current farming practices. Approximately 50 percent of the nitrogen fertilizer applied may be recovered by agronomic crops and 35 percent or less removed in the harvested grain of a crop such as corn. The residual nitrogen is subject to loss by several processes, one being leaching from the crop root zone. Alternative production systems that provide ground water protection must give attention to improved management of nitrogen fertilizer and to practices that minimize the need for nitrogen fertilizer and reduce soil nitrate concentrations. Most important in nitrogen fertilizer management is to more closely match nitrogen availability in the soil with crop needs and to avoid over-fertilization. Nitrogen fertilizer use can be reduced by alternate cropping of low and high nitrogen-demanding crops, use of legumes in the crop rotation to fix nitrogen, and proper use of manures, crop residues, and other organic wastes. Residual nitrates in soil can be reduced by use of cover crops, nitrogen-scavenging crops in the rotation, and alternating shallow and deep-rooted crops. Conservation tillage alone as used with many conventional cropping systems will probably not change the current status of nitrate leaching. Practices used by organic farmers should be carefully studied as possible approaches for ground water protection and adaptation into conservation tillage systems for conserving soil and water resources.

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PAMPANA, SILVIA, ALESSANDRO MASONI, MARCO MARIOTTI, LAURA ERCOLI und IDUNA ARDUINI. „NITROGEN FIXATION OF GRAIN LEGUMES DIFFERS IN RESPONSE TO NITROGEN FERTILISATION“. Experimental Agriculture 54, Nr. 1 (11.10.2016): 66–82. http://dx.doi.org/10.1017/s0014479716000685.

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SUMMARYLegume crops are not usually fertilised with mineral N. However, there are at least two agronomic cases when it would be advantageous to distribute N fertiliser to legume crops: at sowing, before the onset of nodule functioning, and when a legume is intercropped with a cereal. We highlight the impact of various levels of fertiliser nitrogen on grain yield, nodulation capacity and biological nitrogen fixation in the four most common grain legume crops grown in central Italy. Chickpea (Cicer arietinum L.), field bean (Vicia faba L. var. minor), pea (Pisum sativum L.) and white lupin (Lupinus albus L.) were grown in soil inside growth boxes for two cropping seasons with five nitrogen fertilisation rates: 0, 40, 80, 120 and 160 kg ha−1. In both years, experimental treatments (five crops and five levels of N) were arranged in a randomised block design. We found that unfertilised plants overall yielded grain, total biomass and nitrogen at a similar level to plants supplied with 80–120 kg ha−1 of mineral nitrogen. However, above those N rates, the production of chickpea, pea and white lupin decreased, thus indicating that the high supply of N fertiliser decreased the level of N2 fixed to such an extent that the full N2-fixing potential might not be achieved. In all four grain legumes, the amount of N2 fixed was positively related to nodule biomass, which was inversely related to the rate of the N fertiliser applied. The four grain legumes studied responded differently to N fertilisation: in white lupin and chickpea, the amount of nitrogen derived from N2 fixation linearly decreased with increasing N supply as a result of a reduction in nodulation and N2 fixed per unit mass of nodules. Conversely, in field bean and pea, the decrease in N2 fixation was only due to a reduction in nodule biomass since nodule fixation activity increased with N supply. Our results suggest that the legume species and the N rate are critical factors in determining symbiotic N2-fixation responses to N fertilisation.

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Hellmuth, Rebecca, und George Hochmuth. „Managing Nitrogen Inputs and Outputs on a Dairy Farm“. EDIS 2015, Nr. 3 (06.05.2015): 5. http://dx.doi.org/10.32473/edis-ss640-2015.

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In dairy production systems, nitrogen flows through both the forage crops and the dairy cows. Forage crops use nitrogen mineralized from manure for plant growth. Harvested crops are then fed to dairy cows that, in turn, use the nitrogen for their growth and milk production. When the cows excrete a portion of the consumed nitrogen as manure the cycle is renewed. This 5-page fact sheet focuses on the forage production aspect of the nitrogen cycle at a dairy farm. Written by Rebecca Hellmuth and George Hochmuth, and published by the UF Department of Soil and Water Science, March 2015. (Image credit: R. Hellmuth) SL427/SS640: Managing Nitrogen Inputs and Outputs on a Dairy Farm (ufl.edu)

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Sainju, U. M., B. P. Singh und W. F. Whitehead. „Cover crops and nitrogen fertilization effects on soil carbon and nitrogen and tomato yield“. Canadian Journal of Soil Science 80, Nr. 3 (01.08.2000): 523–32. http://dx.doi.org/10.4141/s99-107.

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Cover crops can influence soil properties and crop yield. We examined the influence of legume [hairy vetch (Vicia villosa Roth) and crimson clover (Trifolium incarnatum L.)] and nonlegume [rye (Secale cereale L.)] cover crops and N fertilization (0, 90, and 180 kg N ha−1) on the short- and long-term effects on soil C and N and tomato yield and N uptake. We measured organic C and N (long-term effects), potential C and N mineralization (PCM and PNM) and inorganic N (short-term effects) periodically on a Greenville fine sandy loam (fine-loamy, kaolinitic, thermic, Rhodic Kandiudults) planted with tomato (Lycopersicum esculentum Mill) from April to August in 1996 and 1997 in Georgia USA. Soil C and N concentrations increased early in the growing season with cover crop residue incorporation, but decreased as the residue decomposed. Rye increased organic N and maintained greater levels of organic C and PCM after 3 yr than other treatments. In contrast, hairy vetch and crimson clover increased PNM and inorganic N soon after residue incorporation into the soil and produced tomato yield and N uptake similar to that produced by 90 and 180 kg N ha–1. Nitrogen fertilization increased PNM and inorganic N after split application and tomato yield and N uptake but decreased organic C and N and PCM compared with rye. Compared with 0 kg N ha–1, nonlegume cover crops, such as rye can increase organic C and N and PCM but legume cover crops, such as hairy vetch and crimson clover, can enrich soil N and produce tomato yield and N uptake similar to that produced by 90 and 180 kg N ha−1. Key words: Cover crops, nitrogen fertilization, soil carbon, soil nitrogen, tomato yield

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Pszczółkowska, Agnieszka, Adam Okorski, Jacek Olszewski, Gabriel Fordoński, Sławomir Krzebietke und Alina Chareńska. „Effects of pre-preceding leguminous crops on yield and chemical composition of winter wheat grain“. Plant, Soil and Environment 64, No. 12 (30.11.2018): 592–96. http://dx.doi.org/10.17221/340/2018-pse.

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The after-effects of pre-preceding crops (second year), i.e. legumes and spring wheat, and nitrogen fertilization rate (0, 60, 120 and 180 kg N/ha) on the yield and chemical composition of winter wheat grain were analysed in a field experiment conducted in 2013–2015. Winter wheat was characterized by higher yield when sown after blue lupine (increase of 0.23 t/ha) and faba beans with a determinate growth habit (increase of 0.37 t/ha) than after spring wheat. Grain yield increased significantly with a rise in nitrogen fertilization rate (by 2.03, 3.47 and 4.02 t/ha, respectively). The species of pre-preceding crops had no significant effect on the phosphorus, potassium, magnesium and calcium content of winter wheat grain. Winter wheat grown after faba beans with an indeterminate growth habit was most abundant in nitrogen. The applied nitrogen fertilizer rates did not modify the concentrations of phosphorus, magnesium and calcium in winter wheat grain. The nitrogen content of grain increased significantly with a rise in nitrogen fertilization rates. A significant increase in manganese and zinc levels was observed when spring wheat was the pre-preceding crop and the iron content of grain increased significantly when winter wheat was grown after peas and blue lupine.

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Crews, T. E. „Perennial crops and endogenous nutrient supplies“. Renewable Agriculture and Food Systems 20, Nr. 1 (März 2005): 25–37. http://dx.doi.org/10.1079/raf200497.

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AbstractPerennial cropping systems may achieve significant improvement over annual systems in the synchrony between crop nutrient demands and nutrient supplies. Improvements in nutrient synchrony would result in the reduction of nutrient losses and their associated environmental impacts. A perennial system with high levels of synchrony would also require fewer nutrient inputs, such that it may be possible to develop an agriculture that functions mostly, if not entirely, on nutrient inputs from endogenous sources (i.e., weathering of primary and secondary minerals and biological nitrogen fixation). In this paper I describe three realms of research that will inform the development of relatively high-yielding grain production systems grown on endogenous nutrient supplies: (1) improvement of nutrient synchrony through the development of perennial crops; (2) identification of soils that are in a high nutrient release phase of pedogenesis, which could balance the export of rock-derived nutrients in crop harvests; and (3) optimization of legume density, harvest index and percent nitrogen derived from the atmosphere (%Ndfa) to achieve adequate nitrogen inputs through biological fixation.

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Sainju, U. M., H. P. Singh und B. P. Singh. „Cover crop effects on soil carbon and nitrogen under bioenergy sorghum crops“. Journal of Soil and Water Conservation 70, Nr. 6 (01.11.2015): 410–17. http://dx.doi.org/10.2489/jswc.70.6.410.

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Lupwayi, Newton Z., und Yoong K. Soon. „Carbon and Nitrogen Release from Legume Crop Residues for Three Subsequent Crops“. Soil Science Society of America Journal 79, Nr. 6 (23.10.2015): 1650–59. http://dx.doi.org/10.2136/sssaj2015.05.0198.

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Haider, Tazeem, Muhammad Shahid Farid, Rashid Mahmood, Areeba Ilyas, Muhammad Hassan Khan, Sakeena Tul-Ain Haider, Muhammad Hamid Chaudhry und Mehreen Gul. „A Computer-Vision-Based Approach for Nitrogen Content Estimation in Plant Leaves“. Agriculture 11, Nr. 8 (11.08.2021): 766. http://dx.doi.org/10.3390/agriculture11080766.

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Nitrogen is an essential nutrient element required for optimum crop growth and yield. If a specific amount of nitrogen is not applied to crops, their yield is affected. Estimation of nitrogen level in crops is momentous to decide the nitrogen fertilization in crops. The amount of nitrogen in crops is measured through different techniques, including visual inspection of leaf color and texture and by laboratory analysis of plant leaves. Laboratory analysis-based techniques are more accurate than visual inspection, but they are costly, time-consuming, and require skilled laboratorian and precise equipment. Therefore, computer-based systems are required to estimate the amount of nitrogen in field crops. In this paper, a computer vision-based solution is introduced to solve this problem as well as to help farmers by providing an easier, cheaper, and faster approach for measuring nitrogen deficiency in crops. The system takes an image of the crop leaf as input and estimates the amount of nitrogen in it. The image is captured by placing the leaf on a specially designed slate that contains the reference green and yellow colors for that crop. The proposed algorithm automatically extracts the leaf from the image and computes its color similarity with the reference colors. In particular, we define a green color value (GCV) index from this analysis, which serves as a nitrogen indicator. We also present an evaluation of different color distance models to find a model able to accurately capture the color differences. The performance of the proposed system is evaluated on a Spinacia oleracea dataset. The results of the proposed system and laboratory analysis are highly correlated, which shows the effectiveness of the proposed system.

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NICHOLSON, F. A., B. J. CHAMBERS und P. M. R. DAMPNEY. „Nitrogen value of poultry litter applications to root crops and following cereal crops“. Journal of Agricultural Science 140, Nr. 1 (Februar 2003): 53–64. http://dx.doi.org/10.1017/s0021859602002848.

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The efficiency of poultry litter nitrogen (N) utilization was studied in seven field experiments in eastern England during harvest years 1991 to 1994. Poultry litter was applied at different application rates in winter or spring, prior to sugar beet or potatoes. The mean manure N efficiency based on crop yields was 33% (range 25–43%) for sugar beet and 36% (range 13–66%) for potatoes. For potatoes, the manure N efficiency was greater from spring (mean 43%) than from winter application timings (mean 30%). The manure readily available N applied (i.e. ammonium-N+uric acid-N) and fertilizer N replacement values were well related (P<0·05) for both sugar beet and potatoes. Similarly, there was a good relationship (P<0·001) between the amounts of readily available N applied in the poultry litter dressings and measured elevations in spring soil mineral N supply. Where the poultry litter dressings supplied >600 kg/ha total N to sugar beet, root sugar concentrations were depressed (P<0·05) and amino-N concentrations increased (P<0·01). The soil mineral N supply following harvest of the sugar beet and potato crops was also increased where application rates supplied >600 kg/ha total N. Yield increases were also recorded in cereal crops grown the following season, but only where high rates of manure N (>600 kg/ha) had been applied. The current work has shown that the fertilizer N replacement value of poultry litter can be predicted based on the amounts of total and readily available N applied, providing guidance to farmers on appropriate reductions in inorganic fertilizer N applications to make allowance for poultry litter N supply.