Amount Of Soil Mineral Research Articles

Effects of adding readily available carbon to soil on nitrogen losses from cattle urine patches

ABSTRACT A lysimeter experiment was carried out to investigate the effects of applying readily available carbon (12 or 24 t sucrose ha−1) to soil on nitrogen (N) losses from cattle urine patches. The carbon (C) was readily available to microbes and was applied onto intact soil monolith lysimeters, containing stony silt loam soil, beneath either ryegrass (Lolium perenne)/white clover (Trifolium repens) pasture (RG/WC) or lucerne (Medicago sativa). Cow urine (700 kg N ha−1) was applied in early July 2017, two days after C application. The application of readily available C increased the immobilisation of N in the soil which reduced the amount of soil mineral N. The C-induced immobilisation of N reduced the ammonia oxidising bacteria population growth rate and the amount of nitrate leached by 51–89%. The addition of readily available C had no significant effect on nitrous oxide emissions. These findings were consistent under both RG/WC and lucerne.

Interpretation of soil mineral nitrogen by scoring organic matter and nitrogen management as an “N-score” in the fields of Hokkaido before sugar beet planting

The objective of the present study was to investigate soil mineral nitrogen (N) in agricultural fields and to evaluate the factors that affect it. The amount of soil mineral N (0–100 cm depth) in 33 farming fields in the Hokkaido area, Japan, was investigated in April 2003, 2004 and 2005 (i.e. before sugar beet planting). The mean value and range of soil mineral N were 147 kg ha−1 and 44–750 kg ha−1, respectively. By analyzing six typical fields in detail (soil mineral N: 44–50 kg ha−1), we found that the history of organic matter application and other field management practices drastically affected the amount of soil mineral N. We referred to these histories and practices as “N-scores”. These scores take into account organic matter application and other field management practices by scoring N input using the Hokkaido Fertilizer Recommendations 2002. Soil mineral N was more closely related to the N-score (r = 0.839**, P < 0.01) than to other soil factors (e.g. pH, total C, total N, cation exchange capacity and autoclaved N). These results suggest that valuating organic matter application and other field management practices by scoring N input (N-score) is useful not only for evaluating soil N fertility, which is expressed by soil mineral N, but also for estimating the risk of N leaching.

Co‐incorporation of biodegradable wastes with crop residues to reduce nitrate pollution of groundwater and decrease waste disposal to landfill

AbstractReturn of high nitrogen (N) content crop residues to soil, particularly in autumn, can result in environmental pollution resulting from gaseous and leaching losses of N. The EU Landfill Directive will require significant reductions in the amounts of biodegradable materials going to landfill. A field experiment was set up to examine the potential of using biodegradable waste materials to manipulate losses of N from high N crop residues in the soil. Leafy residues of sugar beet were co‐incorporated into soil with materials of varying C:N ratios, including molasses, compactor waste, paper waste, green waste compost and cereal straw. The amendment materials were each incorporated to provide approximately 3.7 t C per hectare. The most effective material for reducing nitrous oxide (N2O) production and leaching loss of NO3− was compactor waste, which is the final product from the recycling of cardboard. Adding molasses increased N2O and NO3− leaching losses. Six months following incorporation of residues, the double rate application of compactor waste decreased soil mineral N by 36 kg N per hectare, and the molasses increased soil mineral N by 47 kg N per hectare. Compactor waste reduced spring barley grain yield by 73% in the first of years following incorporation, with smaller losses at the second harvest. At the first harvest, molasses and paper waste increased yields of spring barley by 20 and 10% compared with sugar beet residues alone, and the enhanced yield persisted to the second harvest. The amounts of soil mineral N in the spring and subsequent yields of a first cereal crop were significantly correlated to the lignin and cellulose contents of the amendment materials. Yield was reduced by 0.3–0.4 t/ha for every 100 mg/g increase in cellulose or lignin content. In a second year, cereal yield was still reduced and related to the cellulose content of the amendment materials but with one quarter of the effect. Additional fertilizer applied to this second crop did not relieve this effect. Although amendment materials were promising as tools to reduce N losses, further work is needed to reduce the negative effects on subsequent crops which was not removed by applying 60 kg/ha of fertilizer N.

A meta-analysis of sugarbeet yield responses to nitrogen fertilizer measured in England since 1980

SUMMARYThe data from 161 experiments testing the response of sugarbeet yield to nitrogen fertilizer were assembled in a database. Three commonly used N response models (Mitscherlich, linear plus exponential and bilinear) were fitted to each set of fertilizer application rates and the models were then assessed on how well they fitted all the data. The bilinear model was judged the most appropriate model for fitting to beet root yield adjusted to a standard sugar concentration. The optimum N application was determined for each experiment. Attempts were then made to correlate these optima with factors associated with the site and the season (winter rainfall, soil texture, amount of soil mineral N at sowing, sowing date, summer rainfall and harvest date). Beet grown in peat soil never responded significantly to any applied N fertilizer and neither did crops treated recently with organic manure supplying large amounts (&gt;150 kg N/ha) of available N. Variation in N optima between other sites could not be explained by factors that could be used to predict the amount of fertilizer to apply. In the absence of any method to make reliable predictions of variations in fertilizer need, the most economical uniform amount was calculated. At present fertilizer prices and beet values, this amount is between 100 and 110 kg N/ha. It is possible that the N fertilizer need of beet crops does not vary predictably because this variation is an experimental error. The crop needs a reasonably standard application of fertilizer because much N has to be taken up early in the crop's development, rapidly and predominantly from the topsoil that, at this stage, contains most of the small fibrous root system.

Nitrogen losses from grass ley after slurry application surface broadcasting vs. injection

As the livestock numbers on Finnish dairy farms have increased and most fields on dairy farms are under grass, it has become common to spread cattle slurry over grasslands. To estimate environmental effects of recurrent slurry applications, a 5-year field study was performed to compare nitrogen (N) losses to water and ammonia losses to air by volatilization, when cattle slurry was either surface broadcast or injected into clay soil after grass cuttings. Slurry was spread on the grass in summer (1996–1997) or both in summer and autumn (1998–2000). Biomass N uptake before grass harvesting and amount of soil mineral N in spring and autumn were measured and field N balances were calculated. Despite cool weather, up to one third of the ammonium N of broadcast slurries was lost through ammonia volatilization after application in autumn, but injection effectively prevented losses. The mean surface runoff losses of total N were negligible (0.3–4.6 kg ha-1 yr-1) with the highest loss of 13 kg ha-1 yr-1 measured after slurry broadcasting to wet soil in autumn and followed with heavy rains. A substantial part (24–55%) of the applied mineral N was not recovered by the foregoing measurements.;

Benefits of winter legume cover crops require early sowing

Winter cover crops are beneficial, especially legumes that can supply nitrogen (N) to the next crop. The purpose of this study, involving separate experiments carried out at 2 different locations in north-eastern Slovenia, was to determine the most appropriate sowing time (early, early autumn SD1; late, mid autumn SD2; very late, late autumn SD3) for winter legumes (Trifolium subterraneum L., T. incarnatum L., T. pratense L., and Vicia villosa Roth) for the optimal yield of beneficial dry matter and soil N cycling. The control treatment used Lolium multiflorum Lam. For legume cover crops in SD1, from 915.0 (T. subterraneum) to 2495.0 (V. villosa) kg herbage dry matter yield (HDMY)/ha, 52.3 (T. pratense) to 148.4 (T. incarnatum) kg accumulated N (AN)/ha, and 14.5 (T. pratense) to 114.5 (T. incarnatum) kg symbiotically fixed N (Nsymb)/ha was obtained to the end of autumn. Until the spring ploughing-in, which was before maize sowing, legume cover crops in SD1 yielded 1065.0 (T. subterraneum) to 4440.0 (T. incarnatum) kg HDMY/ha, 74.9 (T. subterraneum) to 193.0 (V. villosa) kg AN/ha, and 4.7 (T. subterraneum) to 179.0 (V. villosa) kg Nsymb/ha. All parameters in SD2 were significantly lower than in SD1, whereas the SD3 sowing was not suitable for the legumes. The benefits of legume winter cover crops with regard to symbiotic N fixation were achieved only by early sowing; however, the amount of soil mineral N in late autumn and in early spring was decreased under L. multiflorum more than under the legumes.

Nitrogen from Hairy Vetch (Vicia villosa Roth) as Winter Green Manure for White Cabbage in Organic Horticulture

ABSTRACTThe effect of the nitrogen (N) supply from hairy vetch, grown as winter green manure, on white cabbage was investigated in field trials performed on an organic farm in north-west Germany over two years. Hairy vetch was either used as green manure or harvested. One of two bare soil fallow treatments was supplied with hairy vetch shoot mass to serve as a reference. In 2002 and 2003, hairy vetch and weeds accumulated 136 and 178 kg ha−1 of shoot N and yielded 3.79 and 4.721 ha−1, respectively. After ploughing and planting white cabbage (Brassica oleracea L. convar, capitata var: capitata f. alba) at the beginning of June, the amount of soil mineral N (SMN) in the topsoil layer was investigated biweekly for about 6–8 weeks until canopy. In 2002, a maximum of 121 kg SMN ha−1 for the green manure hairy vetch treatment was reached within 2 weeks, whereas in 2003 a maximum of only 60 kg SMN ha−1 was observed, due to an exceptionally dry and warm season. In 2002, white cabbage shoot yielded an average 4.4 t DM ha−1 (range 3.9–5.1 t ha−1 DM) and had accumulated 153 kg N ha−1 (range 129–178 kg N ha−1). Mean fresh matter yield (FM) of a single head was only 1.2 kg ± 0.1 kg due to severe pest damage. In the following year, the mean head yield was 5.1 kg FM (range 3.4–6.4 kg) and head yield per hectare was 5.8 t DM (range 4.6–7.5 t DM ha−1) with a mean head N uptake of 182 kg ha−1 (range 136–237 kg N ha−1). The relationship between the weighted arithmetic daily mean of SMN for the first 6–8 weeks after the hairy vetch harvest date and the N uptake of cabbage at two sampling dates was significant, as were most correlations between presented core parameters. Although only about 27% of the N supplied in the green manure was apparently recovered in cabbage shoot at final harvest, a balanced field N budget can be ensured by using hairy vetch as a basic N source for a subsequent white cabbage cash crop.

Performance and environmental effects of forage production on sandy soils. II. Impact of defoliation system and nitrogen input on nitrate leaching losses

AbstractA field experiment was conducted over a 4‐year period to determine NO3 leaching losses from grassland on a freely draining sandy soil. The experiment consisted of all combinations of five defoliation systems; cutting‐only (CO), rotational grazing (GO), mixed systems with one (MSI) or two silage cuts (MSII) plus subsequent rotational grazing, and simulated grazing (SG), four mineral nitrogen (N) application rates (0, 100, 200, and 300 kg N ha−1 year−1), and two slurry levels (0 and 20 m3 slurry ha−1 year−1). Due to the high N return by grazing animals, leaching losses in the rotational grazing systems generally were associated with NO3‐N concentrations which exceeded the EU limit for drinking water. NO3 leaching losses in a rotational grazing system could be reduced by lowering the N fertilizer intensity and the inclusion of one or two silage cuts in spring. However, even in the unfertilized mixed systems, N fixation by white clover exceeded the amounts of N removed via animal products, which resulted in NO3‐N concentrations well above the EU limit for drinking water. In terms of leaching losses, the cutting‐only system was the most advantageous treatment. NO3 leaching losses on grassland could be predicted by the amount of soil mineral N at the end of the growing season and by the N surplus calculated from N balances at the field scale. From the results obtained a revised nitrogen fertilization policy and a reduced grazing intensity by integrating silage cuts are suggested.

Disponibilidade de nitrogênio e produtividade de milho e trigo com diferentes métodos de adubação nitrogenada no sistema plantio direto

Este trabalho teve como objetivo avaliar a disponibilidade de N para as culturas de milho e trigo com diferentes métodos de adubação nitrogenada. O estudo foi realizado na Universidade de Cruz Alta, em Latossolo Vermelho Distrófico argiloso, com seis anos no sistema plantio direto. O delineamento experimental foi de blocos ao acaso com quatro repetições. Os tratamentos foram constituídos por combinações de diferentes épocas e doses de aplicação de N. As épocas foram: em pré-semeadura, na semeadura das culturas e em cobertura. As doses foram: zero, 30 e 90kg ha-1 de N para a cultura do milho e zero, 30 e 60kg ha-1 de N para a cultura do trigo. Os valores de N mineral no solo foram afetados pelas doses e épocas das aplicações. A quantidade de N mineral no solo proveniente da adubação nitrogenada na cultura do milho diminuiu rapidamente após a aplicação. A época de aplicação de N, considerando a mesma dose, seja parcelada ou não, não influenciou a produção de matéria seca, N acumulado e produtividade de grãos. Foi observada variação somente entre as doses totais aplicadas, independentemente das épocas. As maiores produtividades de grãos foram obtidas com a utilização das doses mais elevadas de N. Em termos gerais, observou-se que a aplicação parcelada de N, na semeadura e em cobertura, conferiu as melhores produtividades, possivelmente devido a menores perdas de N e a maximização da absorção de N pelas plantas de milho e de trigo.

Dynamics of soil microbial biomass and activity in conventional and organic farming systems

Dynamics of microbial communities during two growing seasons were compared in soils under tomatoes managed by conventional (2- and 4-y rotations), low input, or organic practices. Fumigation extractable carbon (FEC) and nitrogen (FEN), potentially mineralizable N, arginine ammonification and substrate induced respiration (SIR) were significantly higher in organic and low input than conventional systems on most sample dates. Microbial variables were significantly negatively correlated with amounts of soil mineral N in the conventional 4 y system, whereas they were positively correlated with mineral N in the organic system. The C-to-N ratios of material released after fumigation extraction were significantly higher in the conventional than organic soils. In all farming systems, soil moisture was positively correlated with FEC or FEN, but negatively correlated with the C-to-N ratio of the microbial biomass and SIR. Soil temperature was negatively correlated with FEC and FEN, but positively correlated with the C-to-N ratio of microbial biomass.

Integration of nitrate cover crops into sugarbeet (Beta vulgaris) rotations. II. Effect of cover crops on growth, yield and N requirement of sugarbeet

Between 1989 and 1993, 17 experiments tested the effects of autumn-sown cover crops on the yield, processing quality and N nutrition of subsequent sugarbeet crops. Cover crops had no effect on sugarbeet plant population density or pesticide requirement. In nitrogen response experiments, the mean beet yield at the economic optimum was 83 t/ha. The mean N fertilizer requirement was 96 kg N/ha and the N uptake at maximum yield averaged 180 kg N/ha. Cover crops had no effect on yield, fertilizer requirement or N uptake. In addition, cover crops generally had no effect on the efficiency of N fertilizer use, the mineralization of N from the soil organic matter nor the amount of soil mineral nitrogen at sowing or at harvest of the beet crop. Processing quality was also not affected by cover crops. The cost of growing a cover crop ranged from 0 to 50 £/ha. Since these costs cannot be offset against increases in yields or reduced fertilizer application rates, cover crops need to be low cost, i.e. cheap seed and minimal cultivation. Cover crops using volunteer cereals and weeds or farm-saved grain that are established with a single stubble-cultivation should fulfil these criteria.

Modelling seasonal nitrogen, carbon, water and heat dynamics of the Solling spruce stand

Daily flows of water, heat, carbon and nitrogen from 1976 until 1991 were simulated with the one-dimensional models soil —soiln for a 105-year-old spruce stand on an acid brown forest soil at Solling (central Germany). Nitrogen deposition in the area exceeded 40 kg N ha −1 yr −1. Comparisons were made with measured soil water tensions, chloride and mineral nitrogen concentrations in soil water, and tree biomass components. Down to 60-cm depth, the simulated soil water tensions agreed well with measured data when a summer surface resistance of 125 s m −1 was used to calculate potential transpiration. Modelling efficiency (an indicator of agreement between simulations and measurements) for pF-values of soil water tensions ranged from 0.55 to 0.87. At 100-cm depth, the modelling efficiency was only 0.15. The mean value of the chloride concentrations were, at the same time, underestimated. The average deep percolation was 38% of the precipitation. A lower summer surface resistance of 80 s m −1 was necessary to increase the agreement between simulated and measured chloride concentrations, which decreased the deep percolation to 31% of the precipitation. On average, simulation resulted in an accumulation of N in trees (21 kg N ha −1 yr −1 but a decrease of N in soil (7 kg N ha −1 yr −1). Simulated leaching was high (27 kg N ha −1 yr −1) and probably overestimated due to overestimated soil nitrate concentrations below the root zone. To evaluate the carbon and nitrogen model, too few detailed measurements were available on, especially, plant N uptake and amounts of soil mineral N.

Five years of straw incorporation and its effect on growth, yield and nitrogen nutrition of sugarbeet (Beta vulgaris)

SUMMARYIn 1990–92, field experiments were performed at Broom's Barn Experimental Station to study the effect of 5 years' repeated straw incorporation on sugarbeet. Straw incorporation had no effect on plant population density. Processing quality was reduced by incorporated straw but N had a much larger effect. The effect of incorporated straw on the mineral N content of the soils and N uptake by beet was inconsistent, and this may be related to the amount of soil mineral N present when the straw was incorporated. The efficiency of fertilizer use was unaffected by straw incorporation. On Broom's Barn soils when straw was incorporated, the optimal economic N dressing was c. 120 kg N/ha, and in unincorporated plots it was c. 100 kg N/ha. At the optimal economic N rate, incorporated straw increased beet yields.

Residual Soil Nitrogen in Humid Region Wheat Production

The amount of soil mineral N (nitrate + ammonium) present when winter wheat (Triticum aestivum L.) is spring-fertilized is generally not taken into account when making N fertilizer rate recommendations in humid regions. This is partly because overwinter losses of soil N are thought to be extensive, resulting in little field-to-field variability in the amount of N fertilizer needed. Our objectives were to determine: whether significant levels of mineral N exist in the fall in fields planted to winter wheat in the Coastal Plain of Virginia; if so, the extent to which this mineral N remains within the rooting zone through the winter; and whether this residual N affects crop response to spring N fertilization [...]

An analysis of the response of sugar beet and potatoes to fertilizer nitrogen and soil mineral nitrogen.

A statistical analysis was performed to investigate if, and to what extent, the response of sugarbeet and potatoes to fertilizer N depended on the amount of mineral N already present in the soil, soil type, and prior application of organic manures. For this purpose the results of 150 field trials with sugarbeet and 98 with potatoes were used. The analysis was focussed on the within-block stratum of variation in yield, where regression models were fitted to describe the response to N. For both sugarbeet and potatoes the best fit was obtained when not only fertilizer N was taken into account, but also soil mineral N, soil type and prior application of organic manures. The response to fertilizer N was weaker as the amount of soil mineral N was larger. The optimum amount of fertilizer N plus soil mineral N required was larger on sandy soils than on loam and clay soils. The difference was about 20 kg N/ha for sugarbeet and 100 kg N/ha for potatoes. When organic manures were applied prior to the application of fertilizer N, the optimum for both sugarbeet and potatoes was 15-50 N/ha lower than without application of organic manures. (Abstract retrieved from CAB Abstracts by CABI’s permission)