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The surface carbon dioxide (CO₂) fluxes together with the soil microbial biomass and activity in undisturbed soil columns were studied in three growing seasons. Soil columns had six treatments: (1) control without plants; (2) mineral fertilized without plants; (3) no fertilizer and maize plants; (4) mineral fertilized and maize plants; (5) manure and maize plants; (6) mineral fertilized plus manure and maize plants. Soil microbial biomass was measured by substrate-induced respiration (SIR) and microbial activity as fluorescein-diacetate hydrolysing activity (FDA). Treatments had a significant effect (P < 0.001) on CO₂ fluxes, SIR and FDA. The presence of maize increased CO₂ efflux, SIR and FDA compared to unplanted column. Fertilizer + manure treatment resulted in the greatest plant biomass and the greatest CO₂ efflux. Significant correlation (r = 0.680; r = 0.586 in two consecutive years) between SIR and FDA was found.

The paper presents results of 3-year field studies carried out in a split-block design in four replications in the years 2012-2014 at the Agricultural Experiment Station in Mochełek (Poland). The effect of intensification of cultivation technologies on the yield of morphologically diversified cultivars of white (Lupinus albus), yellow (L. luteus) and narrow-leafed lupin (L. angustifolius) was examined. Traditional cultivars of white and yellow lupin gave significantly higher yields than the self-completing ones, as opposed to narrow-leafed lupin in which the self-completing cultivar had higher yields. Increasing expenses on industrial production means caused an increase in the yield of all the studied species. Seed yield of white and narrow-leafed lupin was significantly the highest in high-input technology, while that of yellow lupin in high- and medium-input technology. In all lupin species, insignificant diversification was observed in the number of pods per plant in medium- and high-input technologies as well as in low- and medium-input technologies. A significant increase in the seed yield along with an increasing intensity of the cultivation of traditional and self-completing cultivars of white and yellow lupin, as well as self-completing cultivars of narrow-leafed lupin, resulted mainly from developing a higher number of pods.

A three-year field experiment was conducted from 2000 to 2002 in North-East Poland. Each year three sulphur fertilization rates in the form of sulphate (S-SO^2-₄) and pure (S-S⁰) sulphur were applied: 40, 80 and 120 kg/ha. In the soil horizon at the depth of 0-40 cm the triple rate of S- and S-S⁰) depressed soil reaction. Acidification of soil caused by S-SO^2-₄ became evident already in the first year of the study while that resulting from S-S⁰) application appeared as late as in the third year. The effect of sulphur on soil in the 40-80 cm horizon was irregular. As the sulphur rates increased and the duration of the experiment progressed, sulphates accumulated in soil. In the 0-40 cm soil layer, the increasing rates of sulphur tended to increase the content of N-NH⁺₄. In most objects, the NPK + S fertilization, and especially the single S-SO^2-₄ treatment, caused an increase in N-NO^-₃ in both soil layers compared with the NPK fertilized object. The dose of 120 kg/ha S-SO^2-₄ caused a significant increase in the concentration of available phosphorus in soil in the 0-40 and 40-80 cm layers.

The objective of this study was to investigate the effect of nitrogen (N) management on soil water recharge, available soil water at sowing (ASWS), soil water depletion, and wheat (Triticum aestivum L.) yield and water use efficiency (WUE) after long-term fertilization. We collected data from 2 experiments in 2 growing seasons. Treatments varied from no fertilization (CK), single N or phosphorus (P), N and P (NP), to NP plus manure (NPM). Comparing to CK and single N or P treatments, NP and NPM reduced rainfall infiltration depth by 20-60 cm, increased water recharge by 16-21 mm, and decreased ASWS by 89-133 mm in 0-300 cm profile. However, crop yield and WUE continuously increased in NP and NPM treatments after 22 years of fertilization. Yield ranged from 3458 to 3782 kg/ha in NP or NPM but was 1246-1531 kg/ha in CK and single N or P. WUE in CK and single N or P treatments was < 6 kg/ha/mm but increased to 12.1 kg/ha/mm in a NP treatment. The NP and NPM fertilization provided benefits for increased yield and WUE but resulted in lower ASWS. Increasing ASWS may be important for sustainable yield after long-term fertilization.

Several sets of soil samples were chosen to demonstrate the applicability of the Mehlich 3 extractant for the determination of sulphur (S) in soils. Archived samples from 139 basal soil monitoring plots (BSMS) sampled in 1995 and 2013, samples from eleven long-term field trials sampled in 1981 and 2017, 1167 soil samples from the areas vulnerable to S losses and 720 samples from the non-vulnerable areas sampled in 2010 were chosen for the experiments. Mehlich 3 clearly showed a statistically highly significant decrease in the soil S content caused by reduction of SO₂ emissions in the long-term field experiments from 33 mg/kg in 1981 to 8 mg/kg in 2017 for the median of the untreated controls. Similar results were obtained for BSMS samples, where an average decrease from 26 mg/kg in 1995 to 17 mg/kg in 2013 was found. Mehlich 3 also showed that more than 52% of samples from the areas vulnerable to S losses were in a very low content category in contrast to only 3% of soils from the other areas. Mehlich 3 clearly proved the capacity to distinguish changes in the content of soil S in all studied cases.

The objective of this study was to investigate the influence of excessive sulfur (S) supply on iron plaque formation and arsenic (As) accumulation in rice plants. A combined soil-sand pot experiment was conducted by using two As levels (0, 20 mg/kg) combined with three S concentrations (0, 60, 120 mg/kg). The results showed that excessive S supply significantly decreased As concentration in brown rice, but As concentration in root increased with increasing rate of S supply. Moreover, bioconcentration factors for leaves and stems were 8-35 fold of that for brown rice, indicating that As was mainly accumulated in rice leaves and stems instead of brown rice. Furthermore, excessive S supply significantly decreased translocation factor of As compared to treatment without S supply. These results indicated that excessive S may reduce As translocation from soils and roots to grain. The mechanism could be ascribed to excessive S that induced the decrease of As availability, the increase of iron plaque formation under As stress, and the increase of glutathione in rice leaves and roots. Therefore, excessive S can reduce As accumulation in brown rice exposed to As contaminated soils though it may result in loss of rice yield.

The research aimed at the assessment of the influence of mineral nitrogen (CaNPK) fertilization and lupine cropping on the N₂O emissions from agricultural soil. Observations were collected from CaNPK and Ca fertilization systems (further referred to as NIL due to the absence of nitrogen (N) fertilizers) in two consecutive years (2012 and 2013) on a long-term (since 1923) field experiment in Skierniewice in Central Poland. N₂O emissions from the soil were measured in situ by the means of infrared spectroscopy using a portable FTIR spectrometer Alpha (Bruker). N₂O fluxes from soils treated under CaNPK and NIL treatments were similar. No significant influence of the current treatment or cropping on the N₂O emissions was noted in the CaNPK treated soil. N₂O emissions in 2012 (barley, ammonium nitrate application) and 2013 (lupine, no mineral nitrogen application) were similar (0.17-23.04 g N₂O-N/ha/day, median 4.29 and 0.09-19.46 g N₂O-N/ha/day, median 4.45, respectively). During the growing period of 2012 (barley, ammonium nitrate application), the N₂O-N emissions from the CaNPK treated soil (uncorrected for NIL) represented 1.02% of the applied N dose. In the growing period of 2013 (lupine, no mineral nitrogen application), the yield-scaled N₂O-N emissions from CaNPK and NIL treatments equaled respectively to 4.4 g and 5.4 g N₂O-N per 1 kg of nitrogen accumulated by lupine.

The aim of the study was to evaluate the glomalins content (total glomalin (TG), easily extractable glomalin (EEG) and glomalin-related soil proteins (GRSP)) in the soil under winter wheat from different crop production systems. The experiment involved four different cultivation systems: organic, integrated (INT), conventional (CON), monoculture-conventional (MON). The highest content of TG and GRSP proteins were observed in organic system. A strong positive correlation was observed between the total number of glomalins and dehydrogenase activity and organic matter. A strong correlation between TG and GRSP content was observed (r = 0.93) as well as between EEG and GRSP (r = 0.79). The highest yields of winter wheat were observed in CON (9.12 t/ha) and INT (9.04 t/ha) systems, while the lowest in monoculture (4.47 t/ha).

The study presents the impact of management practices on greenhouse gas emissions (GHG) and nitrogen (N) losses calculated with a denitrification-decomposition model. Two cropping systems were analysed. The first rotation (A) consisted of potato, winter wheat, spring barley and corn. The second (B) included potato, winter wheat, spring barley and clover with grasses mixture. In A1 and B1 scenarios, fluxes were estimated on the basis of mineral fertilizers input, whereas in A2 and B2 scenarios the assessment of emissions was made with regards to manure. The results indicated that the application of manure in A rotation led to the increase of nitrous oxide (N₂O) emission, N leaching, N surplus, crop yields, and the decrease of nitrogen use efficiency higher than in B rotation. Additional doses of manure in A2 scenario increased the potential of the accumulation of soil organic carbon (SOC) and global warming potential (GWP) by 157%. In B2 scenario, SOC augmented more than three-fold but GWP increased only by 10%. The N losses and GHG emissions could be minimised by controlling N application through the implementation of nutrient management plan in which N doses are defined based on the crop needs and soil quality.

A three-year field experiment was conducted from 2000 to 2002 in North-East Poland. Each year three sulphur fertilization rates in the form of sulphate (S- SO₄^2-) and pure sulphur (S-S⁰) were applied: 40, 80 and 120 kg/ha. The most beneficial effect on the yields of cabbage, onion and barley was produced by the rates of 40 and 80 kg S/ha, while the dose of 120 kg S/ha (especially when applied as S-SO₄^2-) reduced the yields of these crops. Increasing rates of sulphur used as a fertilizer caused increased concentration of sulphates in plants up to their luxury accumulation. Irrespective of the test crop species or form of sulphur applied, once the crops terminated their vegetative season, the plants fertilized with sulphur typically contained more total N than those fertilized only with NPK. The S-SO₄^2- fertilization tended to raise the accumulation of N-NO₃^- in the crops, especially during the juvenile phase. The application of 120 kg S-SO₄^2-) /kg caused depressed amounts of potassium in cabbage, onion and in barley during the heading phase.

Soil bacteria are critical to maintain soil fertility. In this study, soil chemical properties, enzyme activities and soil bacterial community from a long-term fertilizer experiment (37 years) were analysed to elaborate the effects of long-term mineral fertilizer application on soil enzyme activities and bacterial community composition. Compared with control treatment, bacterial community richness was reduced in low nitrogen (N) fertilizer and high N fertilizer treatments and increased in high N fertilizer and phosphorus (P), high N fertilizer and potassium (K) (N2K), and high N fertilizer, P and K (N2PK) treatments. The distribution of each phylum and genera was obviously changed and the range of the dominant phyla was not affected in all fertilization treatments. Principal component analysis showed that soil bacterial community in the N2K treatment was clearly different than in the N2PK treatment. The N2PK treatment had much higher available P, total organic carbon, invertase, urease and phosphatase activities than the N2K treatment, which might change soil bacterial community composition. In conclusion, fertilization with combined application of P, K and N in appropriate proportions is an optimum approach for improving soil quality and soil bacterial community abundance in non-calcareous fluro-aquic soils in the North China Plain.

For characterization of the ability of crops to reflect changing soil properties after the addition of ameliorative materials into the soil both pot and rhizobox experiments were provided. In the pot experiment, the influence of the addition of lime and limestone into contaminated Cambisol containing 7.14 mg Cd/kg, 2174 mg Pb/kg, and 270 mg Zn/kg on element availability for spring wheat was tested. The ameliorative materials were added into the pots containing 5 kg of soil in amount of 3 g CaO, and 5.36 g CaCO₃ per kg of the soil. Soil pH reached up to 7.3 in lime treatments compared to 5.7 in control soil. Mobile portion of soil elements (0.01 mol/l CaCl₂ extractable) dropped by 80% for Zn, 50% for Cd, and 20% for Pb, respectively. In both straw and grains of wheat reduced content of elements was observed in limed pots compared to the control ones. For a detailed characterization of the influence of root exudates on the strength of developed complexes in comparison with the bulk soil, short-term rhizobox experiment was set up under identical soil and lime treatments. Generally, the results of rhizobox experiment confirmed the findings from the pot experiment discussed above. Content of elements in shoots and roots of wheat dropped mainly in the case of Cd and Pb. Soil mobile portion of all three tested elements introduced clear depletion curve in control treatment, both limed treatments showed high stability of element complexes almost unaffected by wheat roots.

Leaching is one of the most practical methods for improvement of saline soils and both the quality and the quantity of leaching water play an important role in desalinization of these soils. To determine the effects of different qualities and quantities of leaching water on salinity of drainage water during the growing season of wheat, pot experiments were conducted with a silty clay loam soil, a typical salt-affected soil in an arid region of central part of Iran. The experiment comprised the treatments of three irrigation water salinities (4, 9 and 12 dS/m) and four leaching levels (3, 20, 29 and 37%), using a factorial design with seven replications for each treatment. The results showed that at the beginning of the growing season the drainage water salinity was highest for all treatments. Then it started to decrease and depending on the quality and quantity of leaching water it became nearly constant or continued to decrease until the end of the growing season. The leaching of salts from the soil profile was more efficient during the first few irrigations and thereafter became less efficient. The increase of leaching level had a significant effect on the decrease of drainage water salinity. The comparison with steady-state mass balance of soil salt, sodium and chloride showed that the simple ratio of chloride in irrigation water to chloride in drainage water can be used to estimate the leaching fraction of saline soils with high accuracy.

The objective of this study was to investigate the capability of radish to extract lead from soils contaminated with lead resulting from air pollution. A randomized block experiment design was performed. The soil was contaminated with PbNO₃ and the treatments consisted of 180 (standard), 250, 350, 450, 800 and 1000 mg/kg lead. After development, plants were harvested and divided into shoots and roots. The lead content of each plant part as well as the soil-lead were measured. The results indicated a non-linear positive relation between the lead concentrations in soil and that accumulated in plant roots and shoots. By increasing the lead concentration in soil, its accumulation in plant tissues was also increased. Most of the extracted lead was accumulated in the roots (208.1 mg/kg) compared to shoots (27.25 mg/kg). Since radish can be seeded up to five times a year, and its yield may reach up to 20 t/ha, it can be used to remediate lead-polluted topsoils (0-10 cm).

In order to improve the nutritional value of two-rowed barley grain, two foliar selenium (Se) fertilizers (sodium selenate and sodium selenite) at four rates (0-10-20-40 g/ha) were applied during the growing seasons 2010/2011 and 2011/2012 in a field experiment conducted under semiarid Mediterranean conditions. The grain harvested in the 2010/2011 season accumulated a greater amount of total Se than the grain of the 2011/2012 season. Sodium selenate was much more effectively taken by plants than sodium selenite, and there was a strong and linear relationship between total Se concentration and Se rate in both sodium selenate and selenite. For each gram of Se fertilization, applied as sodium selenate or sodium selenite, the increases of total Se concentration in grain were 44 and 9 μg/kg dry weight, respectively. No increments in total or available Se were observed in soil after harvesting even at the highest doses of either fertilizer. It can be concluded that two-rowed barley would be a good candidate to be included in biofortification programs under Mediterranean conditions to increase Se in animal feeding and in the human diet through beer production.

The efficiency of the application of microbial preparations enhancing soil properties as well as the diversified fertilization of spring wheat nitrogen was evaluated in the field experiment. Factors of the experiment referred to the levels of nitrogen fertilization: 0, 40, 80, 120 and 160 kg/ha as well as the application of microbial preparations, namely, Proplantan (disaccharide, and polysaccharide, lactic acid, carotene, riboflavin, thiamine, amylase, sea salt, minerals), Effective microorganisms (milk bacteria, photosynthetic bacteria, yeast, actinomycetes, moulds) and UG_max microorganisms (lactic acid bacteria, photosynthetic bacteria, nitrogen-fixing bacteria, actinomycetes, macro- and microelements). The quantity of N_min in the soil layer of 0-0.9 m ranged in respective years from 72.8 to 98.5 kg/ha before the spring wheat seeding and from 58.6.8 to 68.2 kg/ha after the crop was harvested, whereas the amount of N mineralization ranged from 18.9 to 53.3 kg/ha. Grain yields of wheat developed at a high level from 3.26 to 8.31 t/ha. To create the biomass, spring wheat plants absorbed nitrogen ranging from 78 kg N/ha in objects not fertilized to 184 kg N/ha in objects fertilized with the dose of 160 kg N/ha, and the share of nitrogen accumulated in the seeds amounted on average to 82% of the total uptake of that element. The highest N use efficiency, N physiological efficiency, N agronomic efficiency and N apparent recovery fraction were detected in objects fertilized with the dose of 40 kg N/ha. Each increase in the level of nitrogen fertilization affected lowering of the values of evaluated fertilization efficiency ratios.

The present studies determined the antagonistic activity of selected fungi of the soil environment of root chicory -a high-inulin plant, with considerable pro-health values - towards such fungi pathogenic towards this plant as: Altenaria alternata, Botrytis cinerea, Fusarium culmorum, F. oxysporum, Thanatephorus cucumeris and Sclerotinia sclerotiorum. The cultivation of root chicory took into consideration soil mulching with cover crops (oats, tansy phacelia and common vetch) as well as the conventional cultivation, i.e. without any cover crops. The total population of fungi after soil mulching with common vetch was almost twice as small as in the control and smaller than with phacelia as a cover plant. Antagonistic Clonostachys spp., Myrothecium spp., Penicillium spp. and Trichoderma spp. displayed differentiated activity towards the studied fungi. The greatest antagonistic effect was observed after the mulch of oats. Besides, oats and common vetch the most positive effect on the antagonistic activity was that of Clonostachys spp., Myrothecium spp., Penicillium spp. and Trichoderma spp. Those fungi were most effective in inhibiting the growth and development of F. oxysporum, T. cucumeris and S. sclerotiorum.

Based on a long-term fertilization experiment on a light soil, a study was conducted on the impact of varied fertilization on the levels of silicon forms available in the soil. It was shown that the exchangeable silicon content in the tested soil was very low, which can have a limiting effect on crop yields. Soil pH is a factor that significantly affects the exchangeable silicon content of the soil. Therefore, under the conditions of acidic soils, liming is a treatment that increases the level of silicon forms available to plants in the soil.

Field experiment was conducted on clay loam soil during winter season of 2010-2011 and 2011-2012 at the Research Farm, Bidhan Chandra Krishi Viswavidyalaya, West Bengal to study the influence of sulphur (S) levels and irrigation on quality and yield of mustard (cv. Varuna, T-59). Results revealed that yield attributes and yield of crop were highest with 60 kg S/ha, mostly at par with 45 kg S/ha. Double irrigation at flower initiation (30 days after sowing (DAS)) and siliqua development stages (60 DAS) was best with respect to growth, yield attributes, yield, S uptake and oil percent in seed. Effects of both S levels and irrigations on glucosinolate and fatty acid content were non-significant except on progoitrin. The erucic:oleic acid ratio was inversely related to the subsequent increase in S doses, thereby suggesting the qualitative improvement of oil with S application. Oil percent has a negative correlation with sinigrin and gluconapin content. The uptake of S was positively correlated with oleic acid content but showed lower or even negative correlation with other fatty acids. Therefore, irrigation (twice at 30 DAS and 60 DAS) in combination with 45 kg S/ha are recommended for improving yield attributes, yield, oil percent and S uptake of Indian mustard.

The field experiment was carried out during 2004-2006. The aim of the study was to determine the influence of insecticides (Actara 25 WG - 0.08 kg/ha, Regent 200 SC - 0.1 L/ha, Calypso 480 SC - three rates: 0.05; 0.075;0.1 L/ha), used for controlling Colorado potato beetle, on total glycoalkaloid (TGA) content in potato leaves and tubers of three cultivars (Mors, Wiking, Żagiel). The insecticides significantly increased (Calypso 480 SC) or decreased (Actara 80 WG, Regent 200 SC) the TGA content in potato leaves, and increased TGA in tubers as compared with tubers harvested from the control. Leaves and tubers of cultivar Mors had the highest TGA contents, whereas Żagiel leaves and Wiking tubers had the lowest levels.

Long-term field experiments are important for assessing the yield response of crops to different tillage systems and pre-crops. An experiment was established in 1996 in Raasdorf (Austria) on a chernozem with four tillage treatments (mouldboard ploughing (MP), no-till (NT), deep conservation tillage and shallow conservation tillage) and two crop rotations. Winter wheat yields were generally at similar levels with all four tillage systems in most years between 1998 and 2012. Yields increased with higher amounts of rainfall during the vegetation period (from October until June) with the smallest increase among tillage treatments in NT. This indicates that MP can be superior to NT regarding yield at higher amounts of rainfall. Pre-crops considerably influenced winter wheat with higher yields after maize, soybean and winter wheat than after sugar beet. In one year with high rainfall, a tillage × pre-crop interaction showed that yields were lower after maize in NT than in other tillage systems whereas yields after sugar beet tended to be higher with NT in years with low rainfall.

The availability of risk elements in soil can be possibly reduced by various soil additives. Among them, the attention has been recently focused on the research of unconventional soil additive - biochar. The aim of this study was (i) to observe the effect of biochar application on risk elements transport through the soil profile and (ii) to assess the availability of risk elements in biochar amended soil to willow growth. The experiment was established at greenhouse conditions and extremely contaminated soil, reaching 43 mg/kg cadmium (Cd) and 4340 mg/kg zinc (Zn), was used. To observe risk element content in leachate, the lysimeter cylinders were tested. The rates of biochar were 0 (control); 5, 10, and 15% per mass of soil. The results showed that biochar significantly increased biomass production whereas the plant Cd and Zn contents remained unchanged in most cases. In leachate, Cd and Zn content decreased by 99% at all the biochar treatments. We can summarize that biochar appears to be a very effective regulator of availability of observed risk elements and improver agent for biomass production of plants and remediation efficiency.

A field trial with four potato cultivars (Faluka, Manitou, Madeleine and Stirling) was conducted in two consecutive years (2012 and 2013) at a laboratory field of Biotechnical Faculty in Ljubljana. The aim of the study was to evaluate different requirements of the selected cultivars in regard to the ridge and tuber cluster. The following parameters were defined and monitored: area of the form surrounding the tubers (ellipse), cross-sectional area of the ridge, vertical and horizontal tuber span in the ridge, the length of semi-axes (a) and (b) of the ellipse, minimum distance of tubers and ellipse from the outer ridge side. The results of 2012 trial indicated that the minimal ellipse method defining the ellipse was not satisfactory as statistical significance was limited due to a large volume of vacant space in the ridge not occupied by potato tubers. Therefore, the mathematical model was upgraded in 2013 and a physical parameter (tuber mass) was incorporated in the equation to better depict the tuber cluster. The trials were designed as a randomized block with five repetitions. The largest ellipse, horizontal tuber span in the ridge and the longest semi-axis (a) were recorded for the cv. Manitou resulting in the highest yield. However, no statistical differences were recorded in the horizontal tuber span, the length of the semi-axis (a) or cross-sectional area of the ridge among cultivars analysed. It was determined that different cultivars require specific growth space in the potato ridge. Moreover, the newly developed method proved efficient for determining growth requirements of potato tubers in the ridge.

The experiments were conducted to study the effects of arsenic-contaminated irrigation water, zinc and organic matter on the mobilization of arsenic in an Aeric Endoaquept in relation to rice (cv. IET 4786). The results show that the amount of extractable arsenic increased with the progress of submergence decreased with zinc application. The magnitude of such decrease varied with the Zn amount, being greater (0.70 to 1.08 mg/kg) in the treatment where zinc was applied at the rate of 20 mg/kg. With regards to organic matter application, the arsenic content in soil markedly decreased, especially with farmyard manure application. The results of the greenhouse experiment with exposure of graded doses of arsenic to rice suggest that the upper toxic limit of arsenic in soil was 10 mg/kg for rice. The results of the field experiment show that the grain yield of continuous flooding (4.84 t/ha) and intermittent flooding up to 40 days after transplanting followed by continuous flooding (4.83 t/ha) with the application of ZnSO₄ at the rate of 25 kg/ha did not vary significantly. The lowest grain yield (3.65 t/ha) was recorded in the treatment where the intermittent flooding was maintained throughout the growth period without the application of zinc. The amount of arsenic was, however, much lower in the treatment where intermittent flooding was maintained throughout the growing period combined with zinc sulphate application.

Cereal/legume intercropping may improve resource use efficiency in agroecosystems and increase yield per unit surface area and yield stability. Two field bean (Vicia faba L.) and four barley (Hordeum vulgare L.) cultivars were mono- and intercropped (additive design) in a 2-year lysimeter experiment on a sandy loam soil. The aim was to test the effect of the cropping system on dry matter and N yield of forage, the residual effect on the subsequent ryegrass crop (Lolium multiflorum Lam. westerwoldicum), and NO₃-N leaching in the rotation. Land equivalent ratios were 1.65 for dry matter and 1.67 for N yield, indicating a clear advantage of the intercrop over sole crops. Both species suffered from competition, especially in terms of N resources, but barley was less affected. Nitrate leaching was the lowest from intercrop. Preceding crop significantly affected dry matter, N content and NO₃-N leaching of ryegrass. Field bean sole crop gave the highest benefits to ryegrass in terms of forage dry matter and N content, but also the highest NO₃-N leaching, followed by the intercrop and the barley sole crop. Barley/field bean intercropping may be an effective strategy to reduce land requirements, N leaching losses and fertilizer inputs, thereby increasing the sustainability of farming systems.

Long-term experiments facilitate the observations of changes in soil properties affected by agricultural activity as well as the reactions of crops to those properties. The aim of the study was the assessment of the relationship between the soil pH as well as contents of organic carbon, total nitrogen, available forms of phosphorus, potassium (K_av), magnesium (Mg_av) and the magnesium content in flag leaves (Mg_fl) in winter wheat. There was also determined the correlations between the Mg_fl content and the nitrogen (N_fl), phosphorus, potassium (K_fl) and calcium (Ca_fl) contents in those leaves. The Mg_fl content was at-the-highest-level linearly positively correlated with soil pH and its richness in Mg_av. The dependence of the Mg_fl content on soil properties and the wheat leaves chemical composition was best described by polynomial equations of the 2^nd degree, except for the K_av and K_fl contents. The Mg_fl content depending on the Mg_av content × soil pH and Mg_av × K_av interaction. The winter wheat containing more N_fl and Ca_fl and less K_fl, accumulated more Mg_fl.

Soil testing in the Czech Republic is based on the use of the Mehlich 3 method for determination of macronutrients and diethylentriaminepentaacetic acid (DTPA) and hot-water extraction for determination of micronutrients. Since inductively coupled plasma optical emission spectrometers have become commonly used in soil testing laboratories, Mehlich 3 extractant could be used very effectively also for a simultaneous micronutrient determination. To take full advantage of the universal Mehlich 3 extractant, new criteria for evaluation of the content of micronutrients in this extractant are needed. The criteria presented in this study were obtained by a simple calculation of criteria from the relationships between the Mehlich 3 extractant and the extraction methods for which the criteria were available (DTPA for copper, zinc, manganese, iron and hot-water extraction for boron). The first calculated estimates of the criteria were pre-validated and slightly adjusted to minimize the difference between the frequency of the samples in each category after determination and evaluation by the compared methods. Further adjustment of the presented critical values with respect to the field and pot experiments will be necessary in the future.

Superior protein quality and consistent processing quality is needed for winter wheat marketing in South China. It has been shown that uniconazole concentration and plant density are certainly related to crop growth. An experiment was conducted to investigate the effects of uniconazole concentration and plant density on nitrogen content and grain quality in winter wheat (Triticum aestivum L.). Trials were managed to provide three levels of density (90 × 10⁴, 180 × 10⁴, and 270 × 10⁴ per ha) over plots receiving four levels of uniconazole concentrations (0, 10, 20, and 40 mg/kg) which were applied to seeds before sowing. The results revealed that the contents of N accumulated in ear, stem, and leaf were higher in uniconazole concentrations than that in control, and the effect of uniconazole on main stem was bigger than that on tillers. The grain protein was significantly (LSD, P < 0.05) higher in uniconazole concentrations than that in control. Uniconazole at 20 mg/kg was the most favorable for improving grain protein and protein fractions. Application of uniconazole concentrations also significantly (LSD, P < 0.05) increased WGC (wet gluten content) and SDS (sedimentation volumes), prolonged DDT (dough development time) and DST (dough stable time), and improved WA (water absorption), increased VV (valorimeter value), and subsequently improved the processing quality of wheat grains. These results suggest that a combination of uniconazole concentration and plant density should be applied in South China.

This study investigated microbial biomass-N (MB-N) and N-mineralization in soils of four different vegetation systems including forest (sal), mixed forest, savanna and cropland ecosystems in the Vindhyan region, India. A change was noted in the above region due to physiographic differences and anthropogenic disturbances. Annually the soil moisture (SM) content across the different study sites ranged from 7.5 to 24.3% being maximum in forest sites compared to savanna and cropland sites. The NH₄⁺-N, NO ^-₃ -N and MB-N concentrations varied from 4.3 to 10.2 μg/g, 1.1 to 5.8 μg/g and 21.3 to 90.2 μg/g dry soil, respectively, with minimum values in the wet and maximum values in the dry season. The trend of seasonal variation in net N-mineralization was similar to that of moisture content but counter to the concentrations of inorganic-N and MB-N. The net N-mineralization rates at different investigated sites ranged from 4.5 to 37.6 μg/g month. Cultivation reduced the N-mineralization and MB-N by 58.5% and 63.5%, respectively. Experiments showed that the percentage contribution of MB-N to total-N was 8.01 to 19.15%. MB-N was positively correlated with the inorganic-N (n = 180,r.80,P < 0.001) but negatively with soil moisture (n = 180, r = 0.79, P < 0.001) and net N-mineralization rates (n = 180, r = 0.92, P < 0.0001). The higher N-mineralization and MB-N in the soil of forest ecosystem was reported compared to savanna and cropland and the order of soil MB-N levels and net N-mineralization followed the sequence: forest (sal) > mixed forest > savanna > cropland.

Two wheat cultivars (Gaocheng8901 and Yumai50) grown were used to investigate the effect of sulphur fertilizer on the glutenin macropolymer (GMP) size distribution and the contents of glutenin subunits in wheat. The results showed that the contents of GMP, high molecular weight glutenin subunit (HMW-GS) and low molecular weight glutenin subunit (LMW-GS) were improved by sulphur fertilizer under lower nitrogen (N) condition in both cultivars. Under normal N (240 kg N/ha) conditions, sulphur application improved the contents of HMW-GS, LMW-GS and GMP within sulphur rates from 30-60 kg/ha, while decreased when sulphur rate of 90 kg/ha. The volume percentage of GMP particles < 60 μm decreased within sulphur rates from 30-90 kg/ha under lower N treatments. Under normal N condition, the volume percentage of GMP particles > 60 μm increased within the sulphur rates from 30-60 kg/ha, while decreased when excessive sulphur of 90 kg/ha was applied. It is suggested that appropriate sulphur fertilizer was favourable for the formation of large GMP particles, but too much of it was unfavourable under normal nitrogen condition. Sulphur fertilizer did not significantly affect the number distribution of GMP particles in both cultivars. The volume percentage of GMP particles > 60 µm was positively correlated with H/LMW-GS (the ratio of HMW-GS and LMW-GS) and GMP content. It indicated that larger GMP particles had more the ratio of HMW-GS and LMW-GS. And the higher the proportion of larger particles, the higher the content of GMP in wheat grain.