Uptake Of Barley Research Articles

Yield and nutrient uptake of barley and camelina amended with manure from cattle fed barley, triticale dried distillers grains with solubles, and flaxseed diets

Since animal diet affects manure properties, it is expected that manures from different diets may elicit differences in crop response. The objective of the study was to assess how application of ma...

Quantifying biological nitrogen fixation of different catch crops, and residual effects of roots and tops on nitrogen uptake in barley using in-situ 15N labelling

Contributions of legume-based catch crops (LBCCs) to succeeding cereals may be significant. We quantified biological N fixation (BNF) and residual N effects of contrasting CC tops and roots. BNF of three LBCCs (red clover, winter vetch, perennial ryegrass-red clover mixture) was quantified in microplots by 15N labelling. Their residual effects on spring barley were tested against two non-LBCCs (perennial ryegrass, fodder radish) after spring incorporation of CC tops or roots in monoliths. Total N accumulated in LBCCs was 153–226 kg N ha−1, of which 62–66 % was derived from BNF in tops and 31–46 % in macro-roots (0–18 cm soil). Macro-roots represented 31–50 % of total plant N. LBCCs showed similar capacity for soil N extraction as non-LBCCs. After incorporation of LBCC residues, the dry matter and N yields of spring barley were comparable to the effect of 50 kg N fertilisation ha−1, whereas no extra N uptake was derived from non-LBCCs. The 15N-based N fertiliser values of LBCC tops were 34–47 % against 26–29 % for non-LBCCs. LBCC roots contributed substantial amounts of N to the system, a source that is usually underestimated. N immobilisation after incorporation of non-LBCCs may hamper the growth of following main crops especially after removing tops.

Effect of Rhizobacteria and Water Quality on Some Soil Properties and Nutrient Uptake of Barley under Water Stress

Effect of Rhizobacteria and Water Quality on Some Soil Properties and Nutrient Uptake of Barley under Water Stress

Soil fertility status and nutrients provided to spring barley (Hordeum distichon L.) by pig slurry

Nutrient recycling using pig slurry is a common agricultural practice to manage the ever-increasing amounts of wastes from the pig industry. This study was conducted in the southeast of Spain to quantify the enrichments in major (N, P, K, Mg) and minor (Zn, Fe, Cu, and Mn) nutrients in soils amended with D1-170 kg N ha-1 (European Union legislated dose) or D2-340 kg N ha-1, and understand the influence of pig slurry on yield and nutrient uptake in two crop seasons of spring barley (Hordeum distichon L.) Compared to control, D2 increased NO3--N by 11.4X to 109 mg kg-1, Olsen-P by 6.9X to 423 mg kg-1, exchange K (2.5X to 1.6 cmol+ kg-1), Mg (1.7X to 1.8 cmol+ kg-1), diethylene-triamine pentaacetic acid (DTPA)-Zn (94X to 18.2 mg kg-1), and Fe (2X to 11.3 mg kg-1). Available NO3--N, Olsen-P, and DTPA-Zn have the best correlations with crop yield and nutrient uptake. These results indicate that the assessment of soil fertility status at 1-mo after pig slurry addition provides a good indicator for potential yield and uptake of barley. However, it is suggested that leachates should be monitored to effectively manage potential releases of nitrate and phosphate into the environment.

The influence of starch pasting properties and grain protein content on water uptake in barley

Steeping is the first operation of malting and its purpose is to increase the water content of the grain up to 43–46%; however, such a simple step encompasses several metabolic processes that affect germination and the final malt quality. The aim of this study was to evaluate the effect of initial grain protein (GP) content and starch pasting properties, measured using the Rapid Visco Analyser (RVA) on water uptake in different barley varieties. The partial least squares (PLS2) regression algorithm was used to compare the two data matrices, the independent block of variables X (RVA data and GP) and the dependent block Y (water uptake at different steeping times). The first two PLS2 loadings explained 65 and 23% of the total variation in water uptake in the barley samples. Water uptake at 1 and 2 h was poorly explained by the PLS2 models, while after 5 h the models explained more than 40% of the variability. The results from this study showed that, although a relationship between GP and water uptake exists, it is not universal for all the varieties, indicating that the relationship between GP and water uptake is varietal dependent. Copyright © 2014 The Institute of Brewing & Distilling

Feasibility of Rock Phosphate and Other Amendments in Preventing P Deficiency in Barley on a P-Deficient Soil in Northeastern Saskatchewan

In the Canadian Prairies, many soils on organic farms are low in available P, and the only alternative is to use external sources to prevent P nutrient deficiency on these soils. A 3-year (2012 to 2014) field experiment was established in spring 2012 on a P-deficient soil near Kelvington, Saskatchewan, Canada, to determine the potential of organic amendments (alfalfa pellets, compost manure, thin stillage and distiller grain dry of wheat), inorganic amendments (rock phosphate granular, rock phosphate fine, wood ash and bone meal ash) and microbial inoculants/products (JumpStart® and MYKE®PRO), applied alone or in a combination with N and/or P commercial fertilizers, in preventing P deficiency and increasing seed yield, N and P uptake of barley. Compared to unfertilized control, N only treatment did not result in any significant increase in seed yield, while application of P alone increased seed yield significantly but to a lesser degree than when both N and P fertilizers were applied together in all 3 years. Rock phosphate did not result in any seed yield benefit, even when applied along with N fertilizer. Wood ash fine increased seed yield of barley significantly only in the presence of N fertilizer, with highest seed yield in the presence of both N + P fertilizers. Seed yield of barley increased moderately with alfalfa pellets, significantly with compost manure, and considerably with distiller grain dry of wheat, but highest seed yield was obtained from thin stillage, which was essentially similar to that obtained from the N + P fertilizer combination. There was no yield benefit from JumpStart or MykePro in any year and only slight benefit from bone meal ash in 2013. The addition of N fertilizer to MykePro or bone meal ash treatments increased seed yield, but highest yield was obtained when both N and P fertilizers were added, suggesting a lack of available P for optimum seed yield. With few exceptions, the response trends of total N and P uptake in seed + straw to the amendments studied were generally similar to those of seed yield. In conclusion, the organic amendment “thin stillage” provided balanced nutrition and produced yield and nutrient uptake of barley similar to balanced N + P fertilizer treatment, and it was closely followed by “distiller grain dry of wheat”, with moderate benefit from compost manure and some benefit from alfalfa pellets. In this extremely P-deficient soil, rock phosphate was not found effective in preventing P deficiency in barley, while wood ash and bone meal ash provided moderate increase in barley yield, with little yield benefit from JumpStart and MykePro, when other nutrients were not limiting in the soil.

Relative Effectiveness of Various Amendments in Improving Yield and Nutrient Uptake under Organic Crop Production

In organic farming, artificial/synthetic inorganic fertilizers/chemicals are not applied to increase crop yields, but adequate amounts of nutrients are essential for sustainable high production from agricultural crops. Two 3-year (2008 - wheat, 2009 – pea, and 2010 - barley) field experiments were conducted on certified organic farms near Spalding (Dark Brown Chernozem – Typic Haploboroll) and Star City (Gray Luvisol – Typic Haplocryalf) in northeastern Saskatche-wan to determine the relative effectiveness of various organic amendments (compost, alfalfa pellets, wood ash, rock phosphate, Penicillium bilaiae, MykePro, or gypsum), and intercropping of non-legume (wheat, barley) and legume (pea) annual crops on seed yield, total biomass yield (TBY) and nutrient uptake in seed + straw of wheat, pea and barley. In 2008, seed yield, TBY and nutrient uptake of wheat increased (but small) with compost and alfalfa pellets. In 2010, seed yield, TBY and nutrient uptake of barley increased substantially with compost and alfalfa pellets and moderately with wood ash. Other amendments had little or no effect on crop yield and nutrient uptake. In 2009, there was no beneficial effect of any amendment on yield and nutrient uptake of pea, most likely due to fixation of N which is the most limiting nutrient in these soils. Intercropping of wheat or barley with pea produced greater seed yield and nutrient uptake per unit land area basis compared to wheat or barley grown as sole crops in most cases. In conclusion, our results suggest potential benefits in improving yield and nutrient uptake of wheat and barley from compost, alfalfa pellets and possibly wood ash, most likely by preventing deficiencies of some nutrients, especially N, lacking in these soils under organic farming. Our findings also suggest the need for future research to determine the feasibility of rock phosphate, Penicillium bilaiae, MykePro, gypsum or other amendments in preventing P and/or S deficiency in organic crops using soils extremely deficient in these nutrients.

Aquaporin-facilitated water uptake in barley (Hordeum vulgare L.) roots.

It is not known to what degree aquaporin-facilitated water uptake differs between root developmental regions and types of root. The aim of this study was to measure aquaporin-dependent water flow in the main types of root and root developmental regions of 14- to 17-d-old barley plants and to identify candidate aquaporins which mediate this flow. Water flow at root level was related to flow at cell and plant level. Plants were grown hydroponically. Hydraulic conductivity of cells and roots was determined with a pressure probe and through exudation, respectively, and whole-plant water flow (transpiration) determined gravimetrically in response to the commonly used aquaporin inhibitor HgCl2. Expression of aquaporins was analysed by real-time PCR and in situ hybridization. Hydraulic conductivity of cortical cells in seminal roots was largest in lateral roots; it was smallest in the fully mature zone and intermediate in the not fully mature ‘transition’ zone along the main root axis. Adventitious roots displayed an even higher (3- to 4-fold) cortical cell hydraulic conductivity in the transition zone. This coincided with 3- to 4-fold higher expression of three aquaporins (HvPIP2;2, HvPIP2;5, HvTIP1:1). These were expressed (also) in cortical tissue. The largest inhibition of water flow (83–95%) in response to HgCl2 was observed in cortical cells. Water flow through roots and plants was reduced less (40–74%). It is concluded that aquaporins contribute substantially to root water uptake in 14- to 17-d-old barley plants. Most water uptake occurs through lateral roots. HvPIP2;5, HvPIP2;2, and HvTIP1;1 are prime candidates to mediate water flow in cortical tissue.

Long-term effect of heavy metal loads on the mycorrhizal colonization and metal uptake of barley

A pot experiment was designed to study the colonization of indigenous arbuscular mycorrhizal fungi (AMF) on barley ( Hordeum vulgare L.) host plant. Soils of the pots were collected from a long-term field microelement loading experiment on calcareous chernozem soil twelve years after 13 heavy metals (Al, As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sr and Zn) were applied once in four doses (0, 30, 90 and 270 mg element·kg -1 d.w.). The biomass production and element accumulation of the host plant, the various colonization values of the arbuscular mycorrhiza fungi (AMF) – such as colonization intensity (M %), arbusculum richness (A %) in the root system and the sporulation intensity (g -1 dry soil) in the rhizosphere – were measured. When considering the twelve-year adaptation process of the AM fungal populations at the various metal loads, a relatively balanced inside mycorrhiza colonization was found, suggesting the potentials for the selection of tolerant fungi in metal contaminated soils. The balanced infection intensity (M %) of the AM fungi and their common strategies with the host plant have resulted a nonsignificant shoot and root biomass production of barley in general. Mycorrhiza sporulation in the root system proved to be much variable and indicated the toxicity of metals and metal rates. Cd, Pb and Sr elements significantly reduced spore numbers, while a value of 34 spores·g -1 soil was counted in the case of Ni in comparison to the control’s 22 spores·g -1 soil value. Stress-defending strategies of the fungal–plant symbiosis, such as the increased arbusculum richness (A %) could be established for the Hg and Pb rates. In the case of Cd an increased root biomass production became a tool for stress alleviation and reduced the metal allocation towards the shoots. Mycorrhiza fungi are part of the common plant–microbe interactions and appropriate defending mechanisms in metal contaminated soils.

Arbuscular mycorrhizal colonization reduces arsenate uptake in barley via downregulation of transporters in the direct epidermal phosphate uptake pathway

*Here, we used barley (Hordeum vulgare) grown in normal and compartmented pots to investigate sensitivity to arsenic (As) in the absence of a positive growth response to arbuscular mycorrhizas (AM). *We tested the hypothesis that upon inoculation with AM fungi downregulation of HvPht1;1 and HvPht1;2 genes (encoding high-affinity inorganic orthophosphate (P(i))-uptake systems in a direct pathway via root epidermis and root hairs) and upregulation of the AM-induced HvPht1;8 (encoding the P(i)-uptake system responsible for transfer of P(i) from the symbiotic interface to cortical cells) play a role in decreased As uptake and hence reduced As sensitivity in AM plants. *Barley did not respond, or responded negatively to colonization by Glomus intraradices in terms of growth. In terms of specific phosphorus (P) uptake (P uptake per g of root) barley was nonresponsive. There was a significant interaction between As treatment and colonization, resulting in a lower As concentration and uptake in AM compared with nonmycorrhizal (NM) plants. *The decreased uptake of As and higher P : As molar ratios in the AM barley can be explained by the operation of the AM pathway as indicated by induction of HvPht1;8 and by down-regulation of HvPht1;1 and HvPht1;2.

Ammonia volatilization, nitrogen in soil, and growth of barley after application of peat manure and pig slurry

Peat is added to manure, because its low pH and capacity to adsorb ammonia (NH3) give it potential to reduce nitrogen (N) loss. Peat manure was prepared by mixing pig slurry with moderately humified Sphagnum peat. Less than 1% of applied ammoniacal N was volatilized as NH3 from peat manure and pig slurry within 8 h of surface application on clay loam soil according to JTI method. Incorporated manures showed even smaller N loss. The low volatilization was due to the adsorption of manure ammoniacal N by peat, and the infiltration of slurry into harrowed, moist clay soil. In another experiment, peat manure was applied on polypropylene fabric without soil contact. Within the first 3 days there was only 9% reduction in the ammoniacal N of peat manure, but the major part of it was lost during several weeks of dry and warm weather. Peat manure did not cause any major improvements on the growth and N uptake of spring barley in spring and early summer as compared with slurry. Moisture deficit limited the availability of ammoniacal N of manures. As compared with surface application, incorporation of manures increased nitrification of ammonium in the soil, and dry matter mass (19–73%) and N uptake of barley. Supplementing manures with inorganic NPK fertilizer increased both dry matter mass (40–98%) and N concentration of barley stand.;

Relation of availability and barley uptake of some potentially toxic elements

A small-plot microelement load field trial was set up on brown forest clay soil with eight elements (Al, As, Cd, Cr, Cu, Hg, Pb, Zn), on 3 levels each (0/30, 90, 270 kg element ha-1). The soil was treated with soluble salts of elements once at initiation (1994). In the seventh year of the experiment (2001) winter barley was the test plant. The total element content was determined in plant samples (shoot, straw, grain) after microwave digestion using cc.HNO3+cc.H2O2. The element composition of the prepared samples was determined using ICP-MS technique. In the experiment toxic effects of treatments and yield loss could not be observed. Zn and As contents in barely shoots were only moderately increased by increasing microelement loads. Effects of Cr, Cu, Hg, Pb and Al treatments could not be observed. On the other hand, Cd accumulation was significant in the shoot. Cd content was also increased both in straw and grain. Results of this experiment prove that Cd remains mobile in the soil-plant system for a long time. Its accumulation can be observed both in vegetative and reproductive parts of plants without toxic symptoms and yield loss.

Characteristics of amino acid uptake in barley

Plants have the ability to take up organic nitrogen (N) but this has not been thoroughly studied in agricultural plants. A critical question is whether agricultural plants can acquire amino acids in a soil ecosystem. The aim of this study was to characterize amino acid uptake capacity in barley (Hordeum vulgare L.) from a mixture of amino acids at concentrations relevant to field conditions. Amino acids in soil solution under barley were collected in microlysimeters. The recorded amino acid composition, 0–8.2 μM of l-Serine, l-Glutamic acid, Glycine, l-Arginine and l-Alanine, was then used as a template for uptake studies in hydroponically grown barley plants. Amino acid uptake during 2 h was studied at initial concentrations of 2–25 μM amino acids and recorded as amino acid disappearance from the incubation solution, analysed with HPLC. The uptake was verified in control experiments using several other techniques. Uptake of all five amino acids occurred at 2 μM and below. The concentration dependency of the uptake rate could be described by Michaelis–Menten kinetics. The affinity constant (K m) was in the range 19.6–33.2 μM. These K m values are comparable to reported values for soil micro-organisms.

Barley (1→3; 1→4)- β-glucan and arabinoxylan content are related to kernel hardness and water uptake

Harder kernels in barley are thought to be a factor affecting the modification of the endosperm during malting by restricting water and enzyme movement within the endosperm. The objective of this study was to investigate the relationship between kernel hardness, water uptake and the endosperm composition in barley. A range of barley samples from 2003 and 2004 crops were analyzed for kernel hardness by the Single Kernel Characterization System, water uptake during steeping and chemical composition of the endosperm including (1→3; 1→4)- β-glucan, arabinoxylan and total protein. Both (1→3; 1→4)- β-glucan and arabinoxylan content of the endosperm were correlated significantly with kernel hardness in barley samples from both 2003 ( r=0.873 and 0.601, respectively, p<0.01) and 2004 seasons ( r=0.764 and 0.501, respectively, p<0.01). Hardness of the kernel was highly correlated with its water uptake in both 2003 and 2004 samples ( r=−0.853 and −0.752, respectively, p<0.01). β-Glucan content of the endosperm was also correlated significantly with the kernel water uptake for both years (2003: r=−0.752, p<0.01; 2004: r=−0.551, p<0.01). Arabinoxylan content of the endosperm was correlated significantly with the kernel water uptake for the 2003 barley but not for 2004 barley (2003: r=−0.523, p<0.01; 2004: r=−0.151, p>0.01). Protein content of the endosperm was not correlated with the kernel hardness in either year. These results demonstrate that endosperm cell wall components may have significant impact on kernel hardness as well as water uptake of barley.

Cadmium uptake in barley affected by iron concentration of the medium: Role of phytosiderophores

Several experiments were conducted using barley (Hordeum vulgare L. cv. Minorimugi) grown hydroponically in a medium containing cadmium (Cd) to clarify the role of phytosiderophores (PS) in chelator-assisted phytoextraction of Cd and the influence of iron (Fe) on Cd uptake. In the first experiment, plants were grown for 7 days in media containing 5 µmol L−1 Cd sulfate (CdSO4), in which the concentration of Fe was 0 or 10 µmol L−1. A marked increase in Cd uptake was obtained in plants grown under the Fe-deficient condition compared with those grown under the Fe-sufficient (10 µmol L−1) condition. In the second experiment, plants were grown for 7 days in media containing 5 µmol L−1 CdSO4, in which the concentration of Fe was 10 or 100 µmol L−1. As a result, the uptake of Cd in plants grown with excess Fe (100 µmol L−1) was significantly lower than the uptake in plants grown under a normal concentration (10 µmol L−1) of Fe. These results indicated that Cd uptake was affected by Fe concentration in the medium and, in particular, a lower concentration of Fe in the media allowed the influx of Cd into plants. Thus, Fe application to the rhizosphere might be effective in reducing Cd concentration in plants. In the third experiment, the ability of solubilizing PS for insoluble Cd mixed with gelatinous Fe was examined. The results showed that PS could solubilize Cd from sulfide of Cd (CdS) gel. In the fourth experiment, roots of Fe-deficient or Fe-sufficient plants were fed with 0 or 10 µmol L−1 mugineic acid (MA), one of the PS, for 4 h in media containing 5 µmol L−1 CdSO4. The uptake of Cd by the plants was not increased with MA. In the fifth experiment, the amount of PS release in Fe-deficient barley suffering from Cd toxicity was measured. Release of PS was partially reduced by 0.05 µmol L−1 CdSO4 and largely reduced by 0.5 or 5 µmol L−1 CdSO4. Based on these results, it was suggested that, when PS were released by roots of grasses to the rhizosphere, PS could mobilize insoluble Cd around the roots. It was also suggested that PS could not convey Cd into the root cells in the form of a PS–Cd complex. Thus, the main role of PS for chelator-assisted phytoextraction of Cd might be the collection of Cd to the rhizosphere, resulting in the enhancement of Cd concentration in the rhizosphere.

Effects of 15N Split‐application on Soil and Fertiliser N Uptake of Barley, Oilseed Rape and Wheat in Different Cropping Systems

AbstractIn intensive farming systems, farmers split up and apply the N fertilization to winter cereals and oilseed rape (OSR) at several dates to meet the need of the crop more precisely. Our objective was to determine how prior fertilizer N application as slurry and/or mineral N affects contributions of fertilizer‐ and soil‐derived N to N uptake of barley (1997), oilseed rape (OSR; 1998) and wheat (1999). In addition, residual fertilizer N effects were observed in the subsequent crop. Since autumn 1991, slurry (none, slurry in autumn, in spring, in autumn plus in spring) and mineral N fertilizer (0, 12 and 24 g N m−2) were applied annually. Each year, the treatments were located on the same plots. In 1997–1999, the splitting rates of the mineral N fertilization were labelled with 15N. Non‐fertilizer N uptake was estimated from the total N uptake and the fertilizer 15N uptake. All three crops utilized the splitting rates differently depending on the time of application. Uptake of N derived from the first N rate applied at the beginning of spring growth was poorer than that from the second splitting rate applied at stem elongation (cereals) or third splitting rate applied at ear emergence or bud formation (all three crops). In contrast, N applied later in the growing season was taken up more quickly, resulting in higher fertilizer N‐use efficiency. Mineral N fertilization of 24 g N m−2 increased significantly non‐fertilizer N uptake of barley and OSR at most of the sampling dates during the growing season. In cereals, slurry changed the contribution of non‐fertilizer N to the grain N content only if applied in spring, while OSR utilized more autumn slurry N. In OSR and wheat, only small residual effects occurred. The results indicate that 7 years of varying N fertilization did not change the contribution of soil N to crop N uptake.

HKT1 Mediates Sodium Uniport in Roots. Pitfalls in the Expression of HKT1 in Yeast

The function of HKT1 in roots is controversial. We tackled this controversy by studying Na+ uptake in barley (Hordeum vulgare) roots, cloning the HvHKT1 gene, and expressing the HvHKT1 cDNA in yeast (Saccharomyces cerevisiae) cells. High-affinity Na+ uptake was not detected in plants growing at high K+ but appeared soon after exposing the plants to a K(+)-free medium. It was a uniport, insensitive to external K+ at the beginning of K+ starvation and inhibitable by K+ several hours later. The expression of HvHKT1 in yeast was Na+ (or K+) uniport, Na(+)-K+ symport, or a mix of both, depending on the construct from which the transporter was expressed. The Na+ uniport function was insensitive to external K+ and mimicked the Na+ uptake carried out by the roots at the beginning of K+ starvation. The K+ uniport function only took place in yeast cells that were completely K+ starved and disappeared when internal K+ increased, which makes it unlikely that HvHKT1 mediates K+ uptake in roots. Mutation of the first in-frame AUG codon of HvHKT1 to CUC changed the uniport function into symport. The expression of the symport from either mutants or constructs keeping the first in-frame AUG took place only in K(+)-starved cells, while the uniport was expressed in all conditions. We discuss here that the symport occurs only in heterologous expression. It is most likely related to the K+ inhibitable Na+ uptake process of roots that heterologous systems fail to reproduce.

Ridging in autumn as an alternative to mouldboard ploughing in a humid-temperate region

In the original ridge tillage system as practiced in the US Corn Belt, ridges are formed during the growing season. Several studies have documented that this can reduce leaching of nutrients and improve fertilizer efficiency. This study was conducted to determine whether ridges formed in autumn can be used as an alternative to ploughing to reduce N leaching during autumn and winter, and thereby increase growth and N uptake of a subsequent unfertilized crop. A factorial field experiment with tillage and residues as factors was conducted during 1998–2000. Tillage treatments were autumn ridging and ploughing. Residue treatments were stubble, stubble + straw and stubble + liquid manure in order to create a gradient of C/N ratios. From the time of harvest until planting of a subsequent barley crop ( Hordeum vulgare L.), inorganic N was determined 11 times in 1998–1999 and 10 times in 1999–2000 in the 0–10, 10–30, 30–60 and 60–90 cm soil layers. Growth and N uptake of barley was quantified nine times in both 1999 and 2000. Barley grain and straw yields were determined. Ridging resulted in lower levels of inorganic N in the 30–90 cm soil layer in November and a significantly higher level of inorganic N in the 0–30 cm soil layer in late April, indicating reduced leaching and increased N availability for the subsequent crop. Ridging significantly increased growth, yield and N uptake of barley whereas incorporation of straw generally reduced growth, yield and N uptake. It is concluded that ridging in autumn has a N conserving effect, and it is suggested that the potential of ridging in autumn as an alternative to ploughing is further investigated in detailed studies of solute movement, N immobilization/mineralization and crop performance.

Effect of Organic Matter Recycling in Long‐Term Fertilization Trials and Model Pot Experiments

Sustainable agriculture implies the use of biological resources. Farmyard manuring (FYM) and ploughing in plant residues have an important role in maintaining soil fertility. Our aim was to study the effect of various combinations of organic and mineral N‐fertilizers on the Corg content of the soil, grain yield, dry matter production, and N uptake of barley. A model pot experiment was set up with spring barley. Large pots were filled with 46 kg sandy loam soil originating from the plots of the “International Long‐term Experiments for Investigating the Effect of Organic and Inorganic Fertilisers,” Keszthely, Hungary. The field experiment, which was set up in 1983, contains three crop rotations with winter wheat, winter barley, and maize. Treatments: 1) inorganic fertilizers only with increasing N doses (N); 2) FYM in every 3rd yr+N; 3) stalk, straw, or green manure+N. Yield results gained in the field experiment with winter barley were also evaluated. In the 18th yr of the experiment, FYM+N resulted in significantly higher Corg content than with treatments 1 and 3. Grain yields in the field trial were the lowest in treatments without organic matter recycling. In the pot experiment, dry matter production and N uptake of the grains and vegetative plant parts were significantly higher in treatments with FYM+N. Our results clearly prove the advantage of FYM combined with mineral fertilization over the other treatments.

Dietary effects on the composition and plant utilization of nitrogen in dairy cattle manure

The influence of dairy cattle feed composition on the manure composition and on the dynamics and plant availability of cattle slurry N was studied. Dairy cows were fed seven different forages either with or without supplemental concentrates. The concentration of N in faeces dry matter varied from 18 to 38 g/kg dry matter and increased with increasing digestibility of the feed. Cattle slurries consisting of a mixture of 0·5 faecal N and 0·5 urinary N were stored according to common agricultural practice in Northern Europe. The mineralization of faecal N during slurry storage was very variable (0·09–0·50). The plant availability of N in the slurries originating from cattle fed with known diets was tested in small, framed field plots with spring barley, under conditions with minimal N losses. The nitrogen uptake in barley was determined and the mineral fertilizer equivalent (MFE) of slurry N was calculated. The net release of mineral N and CO2 from the slurries in soil was also measured in a parallel incubation study. The MFE of cattle slurry N varied from 53 to 75%. After correcting for the measured urine-N/faeces-N ratio and expected ammonia emission, the MFE varied from 51 to 78%. The plant availability and net release of cattle slurry N were influenced by forage type and feeding level. The MFE was negatively correlated with the concentration of crude fibre and neutral detergent fibre (NDF) in the diet, and positively correlated with the dietary protein content. The net release of CO2 from the slurries after 12 weeks in soil was significantly influenced by the concentration of crude fibre in the diet. The plant availability of slurry N was significantly correlated with the ammonium content (R2=0·53) and negatively correlated with the slurry C[ratio ]N ratio (R2=0·67) and the dry matter[ratio ]N ratio (R2=0·58). Residual slurry N left in the soil after harvest of the first crop varied from 0·25 to 0·47 of total slurry N. It is concluded that the fibre and the protein content of cattle diets have a significant influence on the plant availability of cattle slurry N and on the amount of residual slurry N remaining in the soil after the first growing season.