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In the present study, three soils (Ferralsol, Luvisol topsoil, and Luvisol subsoil) were amended with biochars (charcoal, hydrothermal carbonization coal (HTC) of bark, and low-temperature conversion coal of sewage sludge), wheat straw and a control (no amendment) and incubated over a period of 365 days. Each amendment was applied at a rate of 11.29 g C/kg soil. After incubation, the soils were analyzed to retrieve three density fractions (free fraction (FF), intra-aggregate fraction (IAF), and heavy fraction) which were analyzed for total carbon (TC) contents and scanned by fourier transform infrared spectroscopy (FTIR). The biochars and straw significantly increased the TC contents of soils as compared to control. Among soil organic matter (SOM) density fractions, higher TC contents were documented in the FF and IAF from biochar treatments as compared to the straw. The FTIR spectra of the FF from the charcoal and HTC treatments showed the presence of aluminosilicate minerals on surfaces of SOM. There were slight changes in the FF of straw and HTC treatments as compared to spectra of original amendments. The study suggests that the stability of charcoal and HTC in soils is due to the recalcitrant nature of biochar followed by occlusion into soil micro-aggregates.

The purpose of the studies was to establish the quantitative composition of bacteria Bacillus spp. and Pseudomonas spp. and their antagonistic effect towards soil-borne fungi after the cultivation of oats, spring vetch and tansy phacelia as intercrop cover plants. The total population of bacteria in 1 g dry weight of the soil from the experimental combination where mulch of oats was used was larger than in the combination with spring vetch or tansy phacelia. Totally, approximately three times as much Bacillus spp. was obtained from soil samples as compared to Pseudomonas spp. Tests showed that the most isolates of antagonistic bacteria out of the enumerated genera occurred in the soil after oats cultivation, and the least in the soil after the cultivation of tansy phacelia. Antagonistic Bacillus spp. and Pseudomonas spp. inhibited the growth and development of Fusarium oxysporum, Haematonectria haematococca and Thanatephorus cucumeris in the most effective way. The greatest total antagonistic effect of Bacillus spp. and Pseudomonas spp. towards Altenaria alternata, F. culmorum, F. oxysporum, H. haematococca, P. irregulare and T. cucumeris was found out after managing the mulch of oats. The smallest total antagonistic effect of bacteria was observed after managing the mulch of tansy phacelia.

The objective of the present study was to evaluate the effect of P, Ca, S, and/or K and/or Mg application at different rates on the botanical composition, herbage yield and its nutritive value in dehesas developed on calcareous soils. In two growing seasons, 2009/10 and 2010/11, five surface-broadcast fertiliser treatments were applied once in autumn. Two grazing periods were simulated by cutting the pasture in mid-spring and late-spring. Treatment K1, with the highest amount of Ca and without K in its composition, provided higher crude protein values in the herbage than controls in 2009/10. When the effect of each nutrient was analysed separately, a strong and highly positive response of Mg application on herbage production was recorded. A surface application of fertilisers containing 25 kg Mg/ha in autumn could increase herbage yield by 40% under the studied conditions. However, Mg was not applied alone, and thus this increase could be due to an effect of Mg by itself or to a synergistic effect between Mg and other nutrients applied. The application of Ca, P and Mg may also favour the production of high-quality forage by yielding a greater cover of legumes and digestible protein.

The objective of this study was to analyze the effect of tillage systems and nitrogen fertilization on the grain yield and quality of spring wheat and on selected chemical and biological properties of soil. The first order factor was the tillage system: (1) conventional (CT) - shallow ploughing and harrowing after harvest of the previous crop, and pre-winter ploughing; (2) reduced (RT) - only a cultivator after harvest of the previous crop, and (3) no-tillage (NT) - only Roundup 360 SL herbicide (a.s. glyphosate) after harvest of the previous crop. The second order factor was nitrogen dose: (1) 90 kg N/ha and (2) 150 kg N/ha. Higher yields were demonstrated for spring wheat sown in CT and RT systems, compared to the NT system. In addition, grain yield was increased by a nitrogen dose of 150 kg/ha, compared to 90 kg/ha. Contents of protein and wet gluten in the grain were also increased by the higher nitrogen dose. The RT and NT systems were observed to increase the content of organic C, total N and available phosphorus in the soil, compared to the CT system. They also increased the number and mass of earthworms in the soil, compared to the CT system.

We measured the long-term (28 years) sustainability of rice-wheat cropping system under integrated nutrient management practices emphasizing the trends in grain yields, sustainable yield index (SYI) and nutrient budgeting. The data of long-term experiment revealed that grain yield of both rice and wheat declined under control and sub-optimal fertilizer inputs (50% or 75% recommended fertilizer NPK). Negative yield trend (slope) was observed in control plots for rice (-0.0296) and wheat (-0.0070); whereas positive yield trend was observed under treatments receiving organic supplements. The SYI values indicate that rice yields are more sustainable than wheat. Data on apparent nutrient balance showed a deficit of N (-42.2 kg/ha/year), P (-9.1 kg/ha/year) and K (-52.2 kg/ha/year) under control plots. Surprisingly, there was net depletion of K under the organic supplemented plots. Correlation study revealed that apparent balance of K was negatively correlated with SYI (r = -0.921 for rice; r = -0.914 for wheat) and yield slope (r = -0.870 for rice; r = -0.896 for wheat). If the trend of K imbalance is not reversed, the potential to improve N and P fertilizer use efficiency and crop yields will be limited.

The aim of the research conducted on eutric brown soil on the experimental facility of Faculty of Agriculture, University of Zagreb in 2012 and 2013, was to determine the optimal sowing density for two cultivars of white lupin (Teodora and Energy) and a cultivar of narrow-leafed lupin (Arabella). The study included three sowing densities: 60, 75 and 90 germinated seeds/m². The cultivars of white lupin achieved significantly higher seed yield, higher 1000 seed weight, higher weight of seeds per plant and higher protein content in the seed, compared to the cultivar of narrow-leafed lupin. The sowing density had no effect on seed yield, but the increase in sowing density above 60 germinated seeds/m² significantly reduced the number of pods, the number of seeds and seed weight per plant.

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.

An evaluation of the effects of soil structural heterogeneity on maize (Zea mays L.) root system architecture was carried out on plants grown in boxes containing fine soil and clods. The clods were prepared at two levels of moisture (0.17 and 0.20 g/g) and bulk density (ranges 1.45-1.61 g/ml and 1.63-1.79 g/ml). Soil moisture directly affected the probability of clod penetration by maize roots. Primary roots inside the clods manifested morphological deformations in the form of bends. We observed a significant increase of bends per root length at lower soil moisture (P = 0.02). Root diameter and branching density increased, and lateral root length decreased considerably inside the clods. However, once emerging out of the clods and into free soil, values of all three characteristics remained low. While changes in root diameter were caused mainly by clod moisture (P < 0.05), length of lateral roots was related to bulk density (P < 0.01). Branching density was modified exclusively by an interactive effect of both factors (P < 0.05).

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.

In the present paper genetic relationships of twenty varieties of cashew are described on the basis of morphological characters and RAPD (Randomly Amplified Polymorphic DNA) markers. Results obtained for the phenotypic characters based on similarity coefficient were divided into four clusters with 70% similarity. By means of similarity coefficients (SG), cluster I was found to consist of twelve varieties. Cluster II consisted of a single variety, NRCC-1, cluster III consisted of six varieties and cluster IV had only one variety, Vridhachalam-2. The analysis started by using RAPD markers that allowed us to distinguish 20 varieties. A total of 80 distinct DNA fragments ranging from 0.2 to 3.0 kb were amplified by using 11 selected random 10-mer primers. Genetic similarity analysis was conducted for the presence or absence of bands in the RAPD profile. Cluster analysis clearly showed that 20 varieties of cashew grouped into two major clusters based on similarity indices. The first major cluster comprised one minor cluster. The other major cluster was divided into two sub-minor clusters, one sub-minor cluster having three varieties and the other sub-minor cluster was represented by 15 varieties. Among the 20 varieties, Ullal-3 and Dhana (H-1608) showed the highest similarity indices (87%). It was noted that Vengurla-2 and Vengurla-3 were not grouped into a single cluster but Vengurla-4 has 82% similarity to Vengurla-3. The variety Vengurla-2 has very close similarity (85%) with variety Vridhachalam-3 (M-26/2). The analysis of genetic relationships in cashew using morphological traits and RAPD banding data can be useful for plant improvement, descriptions of new varieties and also for assessment of variety purity in plant certification programmes.

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 effects of lead on root, shoot and seedling length, leaf area, number of leaves, plant circumference, seedling dry weight, root/shoot and leaf area ratios of Thespesia populnea L. were determined in greenhouse under natural environmental conditions with and without phytotoxic metal ions at 5, 10, 15, 20, and 25 µmol/l. Lead treatments have a strong influence on the growth and development of T. populnea by reducing significantly (P < 0.05) all the above parameters. Lead treatment at 5-25 µmol/l produced significant (P < 0.05) effects on seedling and root length, plant circumference and seedling dry weight of T. populnea, while lead treatment at 10-25 µmol/l produced significant (P < 0.05) effects on shoot length, number of leaves and leaf area as compared to control. Tolerance in T. populnea seedling at 25 µmol/l of lead treatment was lowest as compared to all other treatments.

An ideal strain for crude oil degradation in saline soils would be one with high salt-tolerance. A novel bacterial strain, Serratia sp. BF40, was isolated from crude oil contaminated saline soils. Its salt-tolerance, surface activity and ability to degrade crude oil in saline soils were evaluated. It can grow in liquid culture with NaCl concentration less than 6.0%. Its surface activity characterized as an efficient surface tension reduction, was significantly affected by salinity above 2.0%. BF40 inoculation could decrease surface tension of soil solutions and facilitate crude oil removal in soils with 0.22-1.20% salinity, but the efficiency was both significantly lower than its biosurfactant addition. The BF40 strain has a high potential for biodegradation of crude oil contaminated saline soils in view of its high surface activity and salt-tolerance, which is the first report of biosurfactant producing by the genus Serratia for petroleum degrading. We suggest that biosurfactant addition is an efficient strategy. Simultaneously, the growing status of the strain and how to boost its surface activity in saline soils should deserve further studies in order to achieve a continuous biosurfactant supply.

The investigation was carried out in 2005, on 30 plots chosen in the Central-Eastern part of the Emilia Romagna region, and cultivated with pear, grapevine and vegetable crops under the organic management system. For each crop, 5 plots with a level of calcium carbonate > 10% and 5 plots with a level of calcium carbonate < 3% were selected. For pear and vine, soil analyses were performed at the depths of 0-20 cm and 20-50 cm, for vegetable at the depth of 0-50 cm. Organic matter content was higher in pear-cultivated plots, followed by grapevine and vegetable crops. Copper application rate, from 1998 to 2004, was higher in pear and grapevine than in vegetable plots. Soil total and DTPA-extractable Cu were higher in pear and grapevine than in vegetable-cultivated plots. Soil DTPA-extractable Cu concentration was higher in the upper horizon than at 20-50 cm soil depth. The increase of total Cu in pear and vine-cultivated plots was combined with the increase of soil inactive Cu.

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 study aimed at evaluating and comparing changes provoked by the water deficit on water relations and nitrogen fixation in two Vigna unguiculata cultivars, as well as at indicating which cultivar is more tolerant under water deficiency. The experimental design used was entirely randomized in factorial scheme, with 2 cultivars (Pitiuba and Pérola) and 2 water regimes (control and stress). The parameters evaluated were the leaf relative water content, stomatal conductance, transpiration rate, nodule number, nodule dry matter, nitrate reductase enzyme activity, ureide concentration and leghemoglobin in nodule. The stomatal conductance of the Pitiuba and Pérola cultivars under water deficit were 0.20 and 0.01 mmol H₂O/m²/s, respectively. The nitrate reductase activity of the plants under stress was significantly reduced in both cultivars. The leghemoglobin in the Pitiuba and Pérola cultivars under water stress had the concentrations of 58 and 41 g/kg dry matter, respectively. The parameters investigated in this study suggest that the Pitiuba cultivar under water deficit suffers from smaller changes, when compared with Pérola cultivar.

A micro-plot field experiment with reduced urea ¹⁵N application was conducted to study the effects of urease inhibitor NBPT (N-(n-butyl) thiophosphoric triamide) and nitrification inhibitor DMPP(3,4-dimethyl-1H-pyrazolium dihydrogen) on the fate of applied urea ¹⁵N; it aimed to find an efficient way to reduce the urea N application rate while improving the agronomic and environmental benefits. Five treatments were installed, i.e., 180 kg N/ha (N₁, conventional application rate), 126 kg N/ha (N₂, reduced to 70% conventional application rate), N₂ + NBPT, N₂ + DMPP, and N₂ + NBPT + DMPP. Compared with treatment N₁, all the other treatments had a significantly higher total ¹⁵N recovery by both soil and plant (P < 0.05 48.20, 41.39, 37.69, 38.85 and 34.83% soil recovery for N₂ + NBPT + DMPP, N₂ + DMPP, N₂ + NBPT, N₂ and N₁treatment, respectively; and 42.68, 40.86, 40.25, 37.18 and 36.30% plant recovery for N₂ + NBPT + DMPP, N₂ + DMPP, N₂ + NBPT, N₂, and N₁ treatment, respectively). In the plant ¹⁵N recovery, the ¹⁵N absorbed in grain/stem was highest in treatment N₂ + NBPT + DMPP. The maize biomass and the maize yield had a slight increase in treatment N₂ + NBPT + DMPP, compared with those in treatment N₁. In sum, for the maize production in study area, N₂ + NBPT + DMPP application method would be a feasible way to ensure the normal maize yield while improving yield quality, saving urea fertilizer, and protecting the environment.

The study of soil enzyme activities under different land use is of importance for exploration of the soil quality evolution and its evaluation during the revegetation at karst area in Nanchuan, Chongqing, China. Seven kinds of land use were chosen as subject, aiming at revealing the changes in soil enzyme activities through experimental and statistical analysis. The results showed that different land use significantly influenced the enzyme activities. Soil urease, invertase, catalase and amylase behaved the different change. A descending order of urease activity was artificial forest, natural forest, shrubbery, grassland, slope field into terrace, rock desertification and farmland. As to invertase and amylase, they have no clear change orderliness with land use change. Moreover, no significant change was observed in catalase activity and the lower value was found in natural forest. The above results cannot reflect the land use effect on the enzyme activities. According to the soil enzyme index (SEI), it can be seen that the SEI changed with an order of natural forest > artificial forest > grassland > shrubbery > farmland > slope field into terrace > rock desertification, which can objectively and fully evaluate the land use change in soil enzyme.

A pot experiment focused on the study of factors influencing thallium transfer from contaminated soils into kale (green cabbage, Brassica oleracea L. var. acephala, variety Winterbor F1) was evaluated. Three different types of topsoils with naturally low content of thallium (heavy, medium and medium-light soil) were used for pot experiments. The soils were contaminated with thallium sulfate to achieve five levels of contamination (0, 0.52, 2.10, 4.20 and 5.88 mg/kg). There were six replicates for each combination (90 pots in the experiment). The first part of the experiment started in the year of contamination (2001) and continued in 2003. The soil samples and the samples of kale (leaves and stalks were sampled separately) were collected and analysed. Kale was found to be able to accumulate Tl without any influence on yield. The highest thallium concentration was found in the leaves of kale in the first year of the experiment and reached 326 mg/kg dry matter. Bioaccumulation factor (Biological Absorption Coefficient - BAC) was found to be over 80 during the first year of the experiment. In the third year the BAC was around 3 for the soil with the highest pH and the highest organic matter content but as high as 15 for an acid soil with the lowest content of organic matter and the lowest Cation Exchange Capacity (CEC) of soils. The content of thallium in the leaves of kale was found to be 7 to 10 times higher than in the stalks in the third year. In the first year this ratio was up to 18. From these findings it can be concluded that the ability of some plants of Brassicacea family, that are planted as common vegetables, to accumulate thallium is very high and can be a serious danger for food chains. Neutral soils high in CEC and organic matter are able to bind thallium more effectively than poor acid soils and the transfer of Tl into plants from these soils is substantially lower. The uptake of Tl from contaminated soils into kale can be very high and without any negative effect on the plant growth. The transfer of Tl into kale decreases with the time necessary to reach the equilibrium between the added Tl and the soil (ageing of a sample).

To better understand how water stress and availability affect the enzyme activity and microbial communities in soil, we measured the changes of organic carbon (OC), bacteria and fungi populations, and endoglucanase and exoglucanase activities in a semiarid soil treated with air-dried primary sewage sludge at a rate of 20 g/kg. The water potentials established for soil incubation were: saturation (SA, 0 bar), field capacity (FC, -0.3 bar), and permanent wilting point (PWP, -15 bar). An irrigation treatment was a drying-rewetting cycle (DWC) between -0.3 to -15 bars. After 0, 20, 60 and 90 days of incubation soils were sampled for analysis. The addition of sewage sludge increased soil OC, endoglucanase and exoglucanase activities significantly. The effects of soil moisture, incubation time and their interactions on OC, and endoglucanase and exoglucanase activities in soil were significant. During 20 days of incubation, OC, endoglucanase and exoglucanase activities decreased significantly. Soils incubated in DWC and FC compared to soils incubated in SA and PWP had lower OC contents due to organic matter mineralization. Organic C, exoglucanase and endoglucanase activities significantly increased with increasing soil water potential. The activities of exoglucanase and endoglucanase in soils incubated in SA were significantly higher than those in soils incubated in PWP.

Phosphorus (P) availability limits crop growth in most of cultivable soils in north-west India. The beneficial rhizosphere microorganisms such as phosphate-solubilising fungi (PSF) were found to increase P availability in soil and improve crop yields. In view of this, field experiments were conducted during 2009-2011 to evaluate the effect of seed inoculation with PSF (Penicillium bilaii) at different rates of fertilizer P on P content in leaves and grain yield of irrigated wheat in India. The soil was low in Olsen P at the Bathinda site and medium at the Ludhiana site. In no-P treatment, PSF significantly increased grain yield by 12.6% over non-inoculated control. The effect of PSF on grain yield was generally more pronounced in a soil with low Olsen-P compared to medium Olsen-P level. Inoculation of PSF along with 50% P fertilizer increased wheat yield equivalent to 100% P with no PSF. Spike density was significantly higher in PSF + 50% P than all the other treatments. There is need to study a long-term effect of Penicillium bilaii on P-fertilizer saving in wheat on soils varying in P availability, pH and P fixation capacity for different wheat-based cropping systems.

The paper compares the quality of Festulolium, Dactylis glomerata and Arrhenatherum elatius at the end of the growing season over three years with the contrasting weather in the Czech Republic. The effect of pre-utilisation dates in June or July on the quality of grass forage in October, November and December (harvest dates) was investigated. In the first two years, Arrhenatherum elatius exhibited higher yields (P < 0.05) than Festulolium and Dactylis glomerata. In all treatments, differences between the species and between the years were inconsistent for organic matter digestibility (OMD) and neutral detergent fibre (NDF) but Festulolium showed the lowest crude protein (CP) in all years and crude fibre (CF) in the first 2 years. The longer re-growth time due to earlier final cut in summer increased the yield and decreased the nutritive value in winter. Yields of DM, OMD and CP content generally declined and the CF content increased with the delay of winter harvest. Significant species harvest date interactions in some years were due to the steep increase of CF and NDF in Festulolium. Based on DM yields and nutritive value, all species have some merits as forage for use in possibly extended grazing season. Festulolium and Dactylis glomerata could be used to extend the grazing period in continental conditions. Arrhenatherum elatius had sufficient quality at both dry and warm end of the growing season due to the fact that Arrhenatherum elatius was a representative of drought-resistant species; however, intense grazing could suppress it.

Four peanut (Arachis hypogaea L.) cultivars (cvs. TPT-1, TPT-4, JL-24 and TMV-2) were grown in open-top chambers at 350 and 600 µmol CO₂/mol in soil amended with 0 (control), 50, 100 and 200 mmol solutions of NaCl. The net photosynthetic rate (P_n), stomatal conductance (g_s), transpiration (E) and dry biomass of leaf, stem and root were measured on 60 days after sowing. The plant growth and photosynthesis increased in both NaCl treated and control plants with elevated CO₂. The g_s and E decreased under elevated CO₂ and the CO₂ effect was highly significant under salt stress mitigating the adverse effect on these components in all the four cultivars tested. A positive correlation was observed between P_n and dry biomass under elevated CO₂ and salt stress. Enhanced CO₂ helps to increase growth and photosynthesis in peanut cultivars and it ameliorates the adverse effects induced by salt stress.

A four-year field experiment was conducted in north-eastern Poland. The aim of the study was to determine the direct and residual effects of increasing doses of meat and bone meal (MBM) on the available phosphorus content of soil and the total phosphorus content in crops above ground biomass or grain. Experimental factor I was MBM dose (1.0, 1.5, 2.0 and 2.5 t/ha/year, and 2.0, 3.0, 4.0 and 5.0 t/ha/every second year), and experimental factor II was the year of the study (four consecutive years). The application of increasing MBM doses to slightly acidic soil insignificantly decreased its pH, but it did not change soil classification. The use of MBM as a fertilizer increased the levels of available phosphorus, compared to the treatments with mineral fertilization. The grain of winter triticale and winter wheat and the green matter of maize contained higher concentrations of phosphorus after the MBM application, in comparison to the plants receiving mineral fertilization. Phosphorus uptake by winter wheat and maize plants (dry matter basis) was higher in treatments with MBM (in particular applied every second year) than in treatments with NPK fertilization. Irrespective of the frequency of MBM application, phosphorus uptake by winter rapeseed was considerably lower, compared to the control plants.

This study was conducted to determine the effect of row spacing (40, 60 and 80 cm) on forage dry matter (DM) yield and quality of four hybrids grown in the years 2001 and 2002. The highest DM yield was obtained from the Arifiye (24.1 and 22.4 t/ha) while the lowest DM yield was obtained from Pioneer 3163 (19.9 and 19.8 t/ha) in the years 2001 and 2002, respectively. As row spacing increased, DM yield as an average of two years decreased from 27.2 to 16.6 t/ha. No differences were found among row spacing for DM content, harvest index (HI) and ear content. As row spacing increased, whole-plant acid detergent fiber (ADF) and neutral detergent fiber (NDF) content increased from 214 to 227 g/kg and from 420 to 451 g/kg during the year 2001, respectively. However, ADF content decreased from 281 to 267 g/kg and NDF contents decreased from 530 to 515 g/kg with increasing row spacing during the year 2002. In this study, hybrids showed distinct differences for crude protein, ADF and NDF contents in both years. Forage quality parameter including ADF and NDF of Pioneer 3163, TTM 8119 and Karadeniz Yildizi were higher than Arifiye hybrid.

The effects of land use practices on soil fauna, especially earthworms, are poorly known in coastal saline agricultural soils. Here we compare earthworm communities in six types of land use practice in the coastal region of China's Bohai Bay, namely uncultivated saline soil, two orchard (pear and winter jujube) lands, man-made forests (chinese ash), vegetable land and cropped land (maize). In addition, we recorded selected physicochemical properties of the soil. Soil organic matter content and total N were significantly higher under pear orchard and vegetable land than under the other land use practices, and their lowest values were observed from uncultivated saline soil. Vegetable land and pear orchard land showed a significantly higher abundance of earthworms than the other land use practices, whereas no earthworm was found in uncultivated saline soil. The sites under individual practices supported one to three earthworm species. Aporrectodea trapezoides species was present under four types of land use practice, and the biomass of this species accounted for more than 60% of the community. Vegetable land and pear orchard land supported richer earthworm community than the other land use practices, dominated by Aporrectodea trapezoides and Drawida japonica. These preliminary results indicated that land use practices have substantial effects on the abundance and composition of earthworm communities in saline soils.

Plant's nitrogen (N) requirement that is not fulfilled by available N in soil has to be supplied externally through chemical fertilizers. A reliable estimate of soil N-supplying capacity (NSC) is therefore essential for efficient fertilizer use. In this study involving a pot experiment with twenty acidic soils varying widely in properties, we evaluated six chemical indices of soil N-availability viz. organic carbon (C_org), total N (N_tot), acid and alkaline-KMnO₄ extractable-N, hot KCl extractable-N (KCl-N) and phosphate-borate buffer extractable-N (PBB-N), based on their strength of correlation with available-N values obtained through aerobic incubation (AI-N) and anaerobic incubation (ANI-N), and also with the dry matter yield (DMY), N percentage and plant (maize) N uptake (PNU). In general, the soils showed large variability in NSC as indicated by variability in PNU which ranged from 598 to 1026 mg/pot. Correlations of the N-availability indices with AI-N and ANI-N decreased in the order: PBB-N (r = 0.784** and 0.901**) > KCl-N (r = 0.773** and 0.743**) > acid KMnO₄-N (r = 0.575** and 0.651**) ≥ C_org (r = 0.591** and 0.531**) ≥ alkaline KMnO₄-N (r = 0.394** and 0.548**) > N_tot (r = 0.297** and 0.273*). Of all the indices evaluated, PBB-N showed the best correlations with plant parameters as well (r = 0.790** and 0.793** for DMY and PNU, respectively). Based on the highest correlations of PBB-N with biological indices as well as plant responses, we propose PBB-N as an appropriate index of N-availability in the acidic soils of India and other regions with similar soils.

The influences of arbuscular mycorrhizal (AM) fungus on growth, gas exchange, chlorophyll concentration, chlorophyll fluorescence and water status of maize (Zea mays L.) plants were studied in pot culture under well-watered and drought stress conditions. The maize plants were grown in a sand and black soil mixture for 4 weeks, and then exposed to drought stress for 4 weeks. Drought stress significantly decreased AM colonization and total dry weight. AM symbioses notably enhanced net photosynthetic rate and transpiration rate, but decreased intercellular CO₂ concentration of maize plants regardless of water treatments. Mycorrhizal plants had higher stomatal conductance than non-mycorrhizal plants under drought stress. The concentrations of chlorophyll were higher in mycorrhizal than non-mycorrhizal plants under drought stress. AM colonization significantly increased maximal fluorescence, maximum quantum efficiency of PSII photochemistry and potential photochemical efficiency, but decreased primary fluorescence under well-watered and droughted conditions. Mycorrhizal maize plants had higher relative water content and water use efficiency under drought stress compared with non-mycorrhizal plants. The results indicated that AM symbiosis alleviates the toxic effect of drought stress via improving photosynthesis and water status of maize plants.

The present study was undertaken to sequentially fractionate nickel (Ni) in soils of divergent physicochemical characteristics and evaluate the contribution of different fractions towards plant uptake. For this, fifteen bulk surface (0-15 cm) soil samples were collected from the cultivated fields of northwestern Indo-Gangetic alluvial plains. A pot experiment was conducted with these soils to assess the contribution of soil Ni fractions to plant uptake using soybean as test crop. Results showed that residual Ni was the most dominant fraction in soil constituting 3.19-63.6% of total Ni. The water soluble plus exchangeable Ni accounted for only 0.70-4.04% of total soil Ni. Organically bound Ni varied from 1.60-6.85% of total Ni; these values are relatively lower as compared to those reported for temperate soils. Correlation studies showed that the free iron oxide (Fe₂O₃) and soil organic carbon correlated with various fractions of Ni in soil. Water soluble plus exchangeable and organically bound are the dominant fractions which contributed positively and manganese oxide (MnO₂) bound and residual fractions contributed negatively towards the phytoavailability of Ni in soil.

Root net primary productivity (RNPP) was assessed in the wet submontane meadow in the highland region of the Czech Republic. RNPP was studied from 1992 to 1995 with help of the in-growth core technique. The effect of different intensities of fertilization on root growth was covered. In comparison with unfertilized stands, the application of fertilizers (90 kg N/ha) resulted, mostly significantly, in greater root productivity (297 g/m²/year and 2.08 g/m²/day, on average). This represented an increase by 72% and 71%, respectively. Variability in the fraction of RNPP to total net primary productivity was examined. Results indicate that this fraction varied from 0.18 to 0.25 across the compared treatments and decreased with increasing fertilization. Data show how different roles can grasslands play in accumulation of plant matter due to different levels of fertilization.