Academic literature on the topic 'Fertilisers (incl. application)'

In 2016 a pot experiment (5 kg of soil – Mitscherlich pots) with 4 treatments (incl. unfertilized control treatment) was established with spring barley, variety KWS Irina, in the outdoor vegetation hall. Haplic luvisol from Jaroměřice nad Rokytnou (with a good supply of magnesium and slightly acid soil reaction – 6.01) was used for this trial. The rates of magnesium (0.075 – 0.15 – 0.3 g Mg per pot) and sulphur (0.1 – 0.2 – 0.4 g S per pot) were increased by using the ESTA Kieserite fertiliser (25 % MgO; 20 % S), treatments 2 – 4. Nitrogen was applied in the form of CAN (27 % N) at a rate of 1 g N per pot in all the treatments incl. the control. The content of post‑harvest soil magnesium and sulphur increased significantly with the applied rate (196 – 227 – 261 mg Mg/kg and 40.1 – 76.8 – 208.6 mg S/ kg, respectively). The soil reaction (pH) increased significantly in all the fertilised treatments (6.42 – 6.57 – 6.60) against the unfertilised control treatment (6.10). Dry matter yields of the aboveground biomass (41.75 – 42.25 – 44.75 – 44.25 g DM per pot) increased significantly only when the two highest rates of fertilisers were applied (44.75 – 44.25 g DM per pot) as against the other treatments.

A two-year small-plot field experiment with the grain maize hybrid KWS 2376 was conducted on heavy soil with a low supply of available nutrients incl. potassium (K) at Otrokovice, Czech Republic, during 2010–2011. The experiment included 4 treatments: unfertilized control; nitrogen (N) fertilisation with urea (120 kg N/ha) alone or combined with two forms of K fertiliser (potassium chloride (KCl) or potassium sulphate (K2SO4); 125 kg K2O/ha). Biomass samples for determination of Zn, Mn, Cu and Fe were taken as the whole aboveground biomass in the DC 32 (first node stage), the ear-leaf in the DC 61 (flowering stage) and grain during the harvest.Between the two years the content of micronutrients in the individual treatments varied irregularly. In DC 32 and DC 61 the order of the content of micronutrients was as follows: Fe > Mn > Zn > Cu. The Fe content was significantly the highest in the unfertilised control and the Mn content after the application of N + K2SO4 in both samplings. In the grain the order was as follows: Zn > Fe > Mn > Cu (mg/kg DM): at the following contents: Zn: 19.20–23.19; Fe: 15.12–19.87; Mn: 0.85–3.60; Cu: 0.19–1.34. We can recommend fertilisation of maize with urea and with both potassium mineral fertilisers without any negative effects on the content of the micronutrients in the maize biomass.

Abstract. The INCA (Integrated Nitrogen in Catchments) model was applied to the River Tweed in the Scottish Borders, a large-scale (4400km2), spatially heterogeneous catchment, draining a wide range of agricultural land-use types, and which contributes approximately 20% of UK river flows to the North Sea. The model was calibrated for the first four years' data record (1994 to 1997) and tested over the following three years (1998 to 2000). The model calibration and testing periods incorporated a high degree of variability in climatic conditions and river flows within the Tweed catchment. The ability of the INCA model to reproduce broad-scale spatial patterns and seasonal dynamics in river flows and nitrate concentrations suggests that the processes controlling first order variability in river water nitrate concentrations have been represented successfully within the model. The tendency of the model to overestimate summer/early autumn baseflow nitrate concentrations during dry years may be linked to the operation of aquatic plant uptake effects. It is, therefore, suggested that consideration be given to incorporating a spatially and temporally variable in-stream plant uptake term for the application of INCA to lowland eutrophic rivers. Scenarios to examine possible impacts of environmental change on nitrate concentrations on the Tweed are examined. These include the effects of (i) implementing different recommendations for fertiliser use and land use change under the Nitrate Sensitive Areas (NSA) Scheme and the Scottish Code of Good Agricultural Practice, (ii) worst case scenario changes linked to a dramatic reduction in livestock numbers as a result of a crisis in UK livestock farming and (iii) changes in atmospheric nitrogen deposition. Keywords: Nitrate, nitrogen, modelling, Tweed, INCA

The pot experiment was established in vegetation hall in the year 2015. Spring barley, variety KWS Irina, was grown. Two different soils – chernozem from Brno (with a low phosphorus content and alkali soil reaction – 7.37) and haplic luvisol from Jaroměřice nad Rokytnou (with a high phosphorus content and slightly acid soil reaction – 6.01) were used for comparison. The rates of phosphorus in the form of triple superphosphate (45 % P2O5) were increased from 0.3 – 0.6 – 1.2 g per pot (5 kg of soil – Mitscherlich pots). Nitrogen was applied in the form of CAN (27 % N) at a rate of 1 g N per pot in all the treatments incl. the control. Using statistical analysis, significant differences were found between the two soil types both in terms of the postharvest soil P content and yields of aboveground biomass. The content of post‑harvest soil phosphorus increased significantly with the applied rate (96 – 141 – 210 mg/kg in chernozem and 128 – 179 – 277 mg/kg in haplic luvisol). Dry matter yields of the aboveground biomass grown on chernozem were the lowest in the control treatment not fertilised with P (38.97 g per pot) and increased significantly with the P rate applied (46.02 – 47.28 g per pot), although there were no significant differences among the fertilised treatments. On haplic luvisol phosphorus fertilisation was not seen at all, demonstrating that the weight of the biomass in all the treatments was balanced (48.12 – 49.63 g per pot).

Abstract. A new version of the Integrated Nitrogen in Catchments model (INCA) was developed and tested using flow and streamwater nitrate concentration data collected from the River Kennet during 1998. INCA is a process-based model of the nitrogen cycle in the plant/soil and in-stream systems. The model simulates the nitrogen export from different land-use types within a river system, and the in-stream nitrate and ammonium concentrations at a daily time-step. The structure of the new version differs from the original, in that soil-water retention volumes have been added and the interface adapted to permit multiple crop and vegetation growth periods and fertiliser applications. The process equations are now written in terms of loads rather than concentrations allowing a more robust tracking of mass conservation when using numerical integration. The new version is able to reproduce the seasonal dynamics observed in the streamwater nitrogen concentration data, and the loads associated with plant/soil system nitrogen processes reported in the literature. As such, the model results suggest that the new structure is appropriate for the simulation of nitrogen in the River Kennet and an improvement on the original model. The utility of the INCA model is discussed in terms of improving scientific understanding and catchment management. Keywords: modelling, water quality, nitrogen, nitrate, River Kennet, River Thames

Abstract. A new model has been developed for assessing the effects of multiple sources of phosphorus on the water quality and aquatic ecology in heterogeneous river systems. The Integrated Catchments model for Phosphorus (INCA-P) is a process-based, mass balance model that simulates the phosphorus dynamics in both the plant/soil system and the stream. The model simulates the spatial variations in phosphorus export from different land use types within a river system using a semi-distributed representation, thereby accounting for the impacts of different land management practices, such as organic and inorganic fertiliser and wastewater applications. The land phase of INCA-P includes a simplified representation of direct runoff, soilwater and groundwater flows, and the soil processes that involve phosphorus. In addition, the model includes a multi-reach in-stream component that routes water down the main river channel. It simulates Organic and Inorganic Phosphorus concentrations in the land phase, and Total Phosphorus (dissolved plus particulate phosphorus) concentrations in the in-stream phase. In-stream Soluble Reactive Phosphorus concentrations are determined from the Total Phosphorus concentrations and the macrophyte, epiphyte and algal biomasses are simulated also. This paper describes the model structure and equations, the limitations and the potential utility of the approach. Keywords: modelling, water quality, phosphorus, soluble reactive phosphorus, basin management

A survey of 'Grassland Egmont' browntop (Agrostis capillaris syn. A. tenuis) seed yields (1987-1989 incl.) showed a range in production from 0 to over 400 kg/ha, with a relatively low average yield (107-147 kg/ha). In order to elucidate the problems associated with growing Egmont for seed, crops on 23 farms were monitored during the 1989/90 growing season. Trends on yield data were then analysed according to precipitation (rainfall or irrigation) and soil type. Precipitation was found to be the major factor in limiting seed yields. With this information, refinements were developed to present management systems including fertiliser application, weed control, irrigation and harvest and post-harvest management. Keywords: browntop, seed production, irrigation, 'Grasslands Egmont'

Sweetpotato (Ipomoea batatas (L.) Lam.) is a major root crop that is widely grown throughout the world. In Australia, sweetpotato is one of the few very profitable and rapidly expanding vegetable crops. The sweetpotato industry is experiencing remarkable growth, with rapid growth in recent decades. However, storage root (SR) size and shape are important for consumer acceptance in developed countries, including Australia, where SRs with an excessively large or small size are rated as low quality with low commercial value. This determines the marketable yield and profit of growers. Agronomical factors have been reported to influence initiation and development of SRs, which affects the size, number and evenness of SRs over time. Environmental factors cannot be manipulated on a large scale. Therefore, this project focused on the influence of nitrogen (N) fertilisation and some local organic amendments to these processes. Also, the chemical changes inside the plants, including soluble sugar and starch, as well as the accumulation of N, were examined during SR initiation. Preliminary experiments were conducted using different soilless cultures to investigate the development of SRs. Three growing methods, nutrient film technique, fine sand and washed (coarse) river sand, were utilised. Results demonstrated that sweetpotato could be grown in the nutrient film technique systems as some SRs formed in the system. However, the observations of SR initiation and development were obstructed as SRs developed under the nutrient film and formed odd shapes. Similarly, fine sand culture was not suitable as it resulted in delayed SR formation and promotion of lignified roots. Washed river sand culture was suitable for SR initiation and development, and was utilised in further studies to examine the initiation of SRs. Results suggested that both deficient (N0) and high (N200) rates of N inhibited the formation of primary cambium at 10 days after transplanting (DAT) and then anomalous cambium (AC) at 21 DAT. Therefore, the initiation of SRs was delayed in those N conditions. Both N0 and N200 treatments had a significantly lower SR rate at 21 DAT whereas both 50 and 100 mg/L N treatments promoted the formation of SRs during this period. Application of N at 100 mg/L was optimal for SR formation as suggested by the highest percentage of SRs during 21 and 56 DAT. In this experiment, treatment N200 had the highest percentage of roots with cambium development in the earliest observation and the highest percentage of initiated SRs between 21 to 56 DAT. This treatment also had the highest starch accumulation in roots during the first 35 DAT. However, sweetpotato required more N after SR formation as indicated by faster growth, higher N acquisition, highest efficiency of N use after 35 DAT and higher carbohydrate accumulation in roots in the N200 treatment. This study indicates that moderate N fertilisation level should be maintained for a few weeks to promote SR formation, and then further N fertiliser should be applied to improve SR development. A pot trial was conducted for Orleans variety to evaluate the effects of different N fertilisation timings on SR initiation, the accumulation of non-structural carbohydrates in plants and the acquisition of N in sweetpotato during the formation of SRs. Both no and delayed N application till 14 DAT inhibited the formation of regular vascular cambium (RVC) and AC during the early stage of adventitious root development. Then, those treatments promoted the lignification of stele cells, resulting in a significantly higher rate of lignified roots. However, plants supplied with N within the first week after transplanting demonstrated significantly higher rates SRs and lower rates of lignified roots. Furthermore, earlier N application promoted plant and root growth as indicated by higher biomass and SR weight, more non-structural carbohydrate and N accumulation in plants, and higher N recovery efficiency. The study indicated that moderate N should be available in soil before or on planting day to promote SR initiation. A pot experiment was set up to investigate the impacts of poultry manure (PM) and sugarcane trash (SCT) on available soil N and total N in dermosol soil and then examined the effects of these products on the initiation of Orleans sweetpotato SRs. The PM treatments increased soil available N and total N whereas SCT application had significantly lower available N in soil. The SCT application at both rates promoted SR initiation and reduced lignification compared to PM and chemical fertilisers. By contrast, both PM applications inhibited the initiation of SRs and promoted lignified roots. Application of PM at 66 tons ha-1 enhanced vine growth and reduced root growth. Both SCT applications maintained shoot growth and promoted root growth. This indicates that SCT should be used for sweetpotato to promote SR initiation and high PM rates should not be applied to sweetpotato as they inhibit SR initiation. This result is in line with our first pot experiment and demonstrate soil organic amendment affects sweetpotaot SR initiaion by changing soil available N. Our study provides agronomic indication that moderate N supply level should be maintained from planting for a few weeks to promote SR initiation, and then another application of N supplied to improve SR development. Soil organic amendments can affect SR initiation due to their impacts on N availability in soil. Therefore, the type and rate should be carefully considered before application.

Abstract Strong acids and chlorinated products are widely utilised for the maintenance of drip irrigation facilities worldwide. This research evaluated low concentration (10 ppm) of hydrogen peroxide (H2O2) products, in drip irrigation water, sourced from H2O2 containing high concentration (30,000 ppm) of an organic stabilizer (H2O2 High) and from H2O2 containing a low concentration (30 ppm) of the same stabiliser (H2O2 Low), evaluated in laboratory and field for effect on drip emitters, seed germination, seedling and crop growth, soil and water parameters. Findings from this research showed that seed germination was not impacted by H2O2 up to 5000 ppm. Positive effects on seed germination were noted for mungbean (Vigna radiata L.), egg plant (Solanum melongena L.), okra (Abelmoshus esculentus L.), chive (Allium porrum L.) and rocket (Eruca sativa L.) treated with 100 ppm H2O2. H2O2 High up to 1000 ppm did not negatively impact seed germination in other species tested. Root and shoot growth were enhanced in some species at lower concentration of H2O2 High, but were negatively impacted by higher H2O2 High concentrations for all crops except for corn. The negative effects on root and shoot growth were generally noted at higher concentrations (>1000 ppm). Therefore, continuous injection of H2O2 at low concentration (<100 ppm) in irrigation is unlikely to affect the seed germination and seedling growth. The impact of continuous injection of 10 ppm H2O2 on drip irrigation performance was evaluated in field trials. The emitter flowrates for surface drip single use tape on a chili (Capsicum frutescens L.) crop was not affected after 6 months of irrigation in either the control or H2O2 treatments. However, for above ground drip for table grapes (Vitis vinifera L.) and in subsurface drip for sugarcane (Saccharum officinarum L.) installations over four years, the emitter flow rate remained higher (2-16%) for H2O2 Low compared to H2O2 High and control. In aboveground drip, emitter clogging was reduced by 50% in H2O2 Low compared to the control and H2O2 High. The yield increases of 25, 10 and 4% in the sugarcane, chilli, and grape respectively probably due to H2O2 delivery proximal to root mass. H2O2 breakdown in soil was rapid, hence no residual H2O2 was found 10 minutes post irrigation. In tertiary treated wastewater (effluent), a single dose of H2O2 20 ppm was effective for suppression of algal blooms, whereas complete elimination was achieved by 2000 ppm by both products. In a circulating irrigation system, the emitter flow ceased after 900 hours due to biofouling in H2O2 High. In a bamboo (Bambusa spp. L) field trial using 20 ppm of products in non-circulating irrigation over 1966 hours, emitter flowrates were reduced by 50%. Drip emitter clogging was significantly reduced to19% for the H2O2 Low and 28% for H2O2 High compared to control (37%) of algae for effluent irrigation water. H2O2 High, unlike H2O2 Low, caused rapid emitter clogging in recirculating hard water irrigation, suggesting that HEDP in the presence of H2O2 caused Ca precipitation resulting in sudden emitter clogging. The degree of Ca precipitation in hard water increased with increasing HEDP inputs in irrigation. pH buffering of hard water delayed Ca precipitation. In the non-circulating irrigation higher concentration HEDP treatment in the hard water irrigation caused rapid emitters clogging. Low pH (≤6) increased solubility of Ca ions whereas higher pH led to precipitation causing crystal and amorphous Ca deposits. Continuous injection of H2O2 (10-20 ppm) in irrigation over a longer term did not show decline of soil biological functions (soil respiration, soil microbial biomass carbon and soil microbial diversity). H2O2 increased corn (Zea mays L.) yield by 9.2 and 70%, and coriander (Coriandrum sativum L.) yield by 2.3 and 15% for plants grown in vertisol and ferrosol, respectively, suggesting interaction effects, due to disproportionally greater decomposition of H2O2 to oxygen in ferrosol. In general, H2O2 Low injection in irrigation resulted not only in improved emitter performance, but also positive effects of crop growth, without noticeable negative impacts on soil. H2O2 High can acidify the rhizosphere, which may be of advantage in alkaline soil and/or irrigation water.