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1.
ABSTRACT

A greenhouse experiment was conducted to study the effect of different irrigation levels (100%, 75%, and 50% of water requirement) and wheat straw biochar levels (0%, 1.25%, 2.5%, 3.75%, and 5% w/w) on faba bean yield, water productivity, root length density, and different ions concentration in soil solution, using a factorial arrangement in complete randomized design with three replications. Results showed that application of high level of biochar (5% w/w) destroyed the plants before they reached maturity. The maximum yield was obtained in 1.25% w/w biochar under full irrigation, while the maximum water productivity was obtained in 2.5% w/w biochar and 50% of water requirement. Further, the root length density in soil top layer (0–8 cm) was significantly more than those in 8–16 cm, due to holding more water content in top layer and no drainage from the pots. Sodium, potassium, calcium and magnesium ions’ concentrations in soil solution were significantly increased by increasing biochar levels; however, the rate of increase in potassium was higher than other ions due to high potassium concentration in biochar in comparison with the soil. In conclusion, application of biochar in the level of 1.25% w/w is suggested as a suitable agent to decrease water consumption and improving the crop performance.  相似文献   

2.
Field screening of 83 groundnut cultivars was undertaken for two seasons to assess their tolerance of salinity based on plant mortality and yield attributes. During the dry season, soil salinity of 4 dS m?1 at sowing and 6–7 dS m?1 21–98 days after sowing (DAS) caused high mortality without seed formation in any cultivars, however, at salinity 4.5 dS m?1 during sowing and 3.5–3.0 dS m?1 15–80 DAS during wet season, 61 cultivars produced seed. The cultivars ‘VRI 3’, ‘UF 70–103’, ‘TKG 19A’, ‘S 206’, ‘Tirupati 4’, ‘M 522’, ‘Punjab 1’, ‘BG 3’, ‘Somnath’ and ‘ICGV 86590’, with high plant stand during both the seasons and over 75 g m?2 seed yield during wet season, were identified salinity tolerant. However, 15 cultivars with more than 50 g m?2 seed yield were moderately tolerant and 28 cultivars with less than 25 g m?2 seed yield were sensitive to salinity.  相似文献   

3.
Most of the crop salt tolerance studies are often conducted in a glasshouse and are limited under field conditions. Therefore, the present research study was conducted under field conditions to evaluate the performance of six wheat cultivars at five salinity levels (EC 0, 3, 6, 9, and 12 dS m?1) in split plot design with three replications. Increasing salinity significantly increased soil pH, electrical conductivity (EC), and sodium adsorption ratio (SAR). Yield parameters of different cultivars were affected more at higher salinity levels than lower in two years. Data over two years revealed that up to EC 9 dS m?1 cultivars PBW 658 and HD 2967 performed ???better on the absolute yield basis but PBW 621 produced ?higher relative yield. At EC 12 dS m?1, PBW 658 produced significantly higher grain yield (4.23 t ha?1) than cultivars HD 2967 (4.11 t ha?1) and PBW 621 (3.99 t ha?1); therefore, should be preferred at salinity more than 9 dS m?1.  相似文献   

4.
In order to investigate the effects of nitrogen (N) and zinc (Zn) fertilizers on seed yield, oil percentage, glucosinolate content, and nutrient uptake of canola (Brassica napus L. cv. Okapi), irrigated with saline and ultra-saline water, field experiments were conducted in Agriculture Research Centre of East Azarbaijan, Iran, during three consecutive years: 2011, 2012, and 2013. The experiments were carried out based on randomized complete block design arranged in factorial with three replications. The experimental treatments included N rates at three levels (0, 50, and 100 kg ha?1), Zn rates at three levels (0, 5, and 10 kg ha?1), and saline water at two levels (8 and 16 dS m?1 as saline and ultra-saline water). According to the results, N and Zn application had a significant effect on the plant height, pod number per plant, and seed yield. However, the value of these traits decreased as a result of the higher salinity level (from 8 to 16 dS m?1). From the results, the glucosinolate content was not affected by N or Zn fertilization, whereas, salinity increased the glucosinolate content from 27.51% to 30.06% when saline water and ultra-saline water were applied, respectively. In addition, the effect of ultra-saline water on the decrease in the N, phosphorous, potassium, and calcium uptake and the increase in the sodium and chlorine accumulation in canola seed was significant. However, Zn application could diminish adverse effects of salinity on phosphorus uptake. For instance, under ultra-saline water conditions, application of 10 kg ha?1 Zn increased the seed phosphorus content compared with control treatment. In general, it seems that nutrients’ supply, especially N and Zn, can be considered as an effective solution to diminish adverse effects of salinity.  相似文献   

5.
Low soil fertility and soil acidity are among the major bottlenecks that limit agricultural productivity in the humid tropics. Soil management systems that enhance soil fertility and biological cycling of nutrients are crucial to sustain soil productivity. This study was, therefore, conducted to determine the effects of coffee‐husk biochar (0, 2.7, 5.4, and 16.2 g biochar kg?1 soil), rhizobium inoculation (with and without), and P fertilizer application (0 and 9 mg P kg?1 soil) on arbuscular mycorrhyzal fungi (AMF) root colonization, yield, P accumulation, and N2 fixation of soybean [Glycine max (L.) Merrill cv. Clark 63‐K] grown in a tropical Nitisol in Ethiopia. ANOVA showed that integrated application of biochar and P fertilizer significantly improved soil chemical properties, P accumulation, and seed yield. Compared to the seed yield of the control (without inoculation, P, and biochar), inoculation, together with 9 and 16.2 g biochar kg?1 soil gave more than two‐fold increment of seed yield and the highest total P accumulation (4.5 g plant?1). However, the highest AMF root colonization (80%) was obtained at 16.2 g biochar kg?1 soil without P and declined with application of 9 mg P kg?1 soil. The highest total N content (4.2 g plant?1) and N2 fixed (4.6 g plant?1) were obtained with inoculation, 9 mg P kg?1, and 16.2 g biochar kg?1 soil. However, the highest %N derived from the atmosphere (%Ndfa) (> 98%) did not significantly change between 5.4 and 16.2 g kg?1 soil biochar treatments at each level of inoculation and P addition. The improved soil chemical properties, seed yield, P accumulation and N2 fixation through combined use of biochar and P fertilizer suggest the importance of integrated use of biochar with P fertilizer to ensure that soybean crops are adequately supplied with P for nodulation and N2‐fixation in tropical acid soils for sustainable soybean production in the long term.  相似文献   

6.
Strawberry is listed as the most salt sensitive fruit crop in comprehensive salt tolerance data bases. Recently, concerns have arisen regarding declining quality of irrigation waters available to coastal strawberry growers in southern and central California. Over time, the waters have become more saline, with increasing sodium (Na+) and chloride (Cl?). Due to the apparent extreme Cl? sensitivity of strawberry, the rising Cl? levels in the irrigation waters are of particular importance. In order to establish the specific ion causing yield reduction in strawberry, cultivars ‘Ventana’ and ‘Camarosa’ were grown in twenty-four outdoor sand tanks at the ARS-USDA U. S. Salinity Laboratory in Riverside, CA and irrigated with waters containing a complete nutrient solution plus Cl? salts of calcium (Ca2+), magnesium (Mg2+), Na+, and potassium (K+). Six salinity treatments were imposed with electric conductivities (EC) = 0.835, 1.05, 1.28, 1.48, 1.71, and 2.24 dS m?1, and were replicated four times. Fresh and dry weights of ‘Camarosa’ shoots and roots were significantly higher than those of ‘Ventana’ at all salinity levels. Marketable yield of ‘Camarosa’ fruit decreased from 770 to 360 g/plant as salinity increased and was lower at all salinity levels than the yield from the less vigorous ‘Ventana’ plants. ‘Ventana’ berry yield decreased from 925 to 705 g/plant as salinity increased from 0.835 to 2.24 dS m?1. Relative yield of ‘Camarosa’ decreased 43% for each unit increase in salinity once irrigation water salinity exceeded 0.80 dS m?1. Relative ‘Ventana’ yield was unaffected by irrigation water salinity up to 1.71 dS m?1, and thereafter, for each additional unit increase in salinity, yield was reduced 61%. Both cultivars appeared to possess an exclusion mechanism whereby Na+ was sequestered in the roots, and Na+ transport to blade, petiole and fruit tissues was limited. Chloride content of the plant organs increased as salinity increased to 2.24 dS m?1 and substrate Cl increased from 0.1 to13 mmolcL?1. Chloride was highest in the roots, followed by the leaves, petioles and fruit. Based on plant ion relations and relative fruit yield, we determined that, over the range of salinity levels studied, specific ion toxicity exists with respect to Cl?, rather than to Na+ ions, and, further, that the salt tolerance threshold is lower for ‘Camarosa’ than for ‘Ventana’.  相似文献   

7.
The aim of this study was to determine the salt tolerance of pepper (Capsicum annuum L.) under greenhouse conditions and to examine the interactive effects of salinity and nitrogen (N) fertilizer levels on yield. The present study shows the effects of optimal and suboptimal N fertilizer levels (270 kg ha?1 and 135 kg ha?1) in combination with five different irrigation waters of varying electrical conductivity (EC) (ECiw = 0.25, 1.0, 1.5, 2.0, 4.0, and 6.0 dS m?1) and three replicates per treatment. At optimal N level, yield decreased when the irrigation water salinity was above ECiw 2 dS m?1. At the suboptimal N level, a significant decrease in yield occurred only above ECiw 4 dS m?1. At high salinity levels the salinity stress was dominant with respect to yield and response was similar for both N levels. Based on the results it can also be concluded that under saline conditions (higher than threshold salinity for a given crop) there is a lesser need for N fertilization relative to the optimal levels established in the absence of other significant stresses.  相似文献   

8.
The effects of salinity on four faba bean (Vicia faba L) cultivars [Giza 429, Giza 843, Misr 1 (Orobanche-tolerant), and Giza 3 (Orobanche-susceptible)] and soil properties were investigated in a pot experiment with addition of 0, 50, and 100 mM sodium chloride (NaCl) for 9 weeks. Salinity significantly decreased calcium (Ca2+), magnesium (Mg2+), potassium (K+), bicarbonate (HCO3 ?), and sulfate (SO4 2?) while significantly increasing sodium (Na+), chloride (Cl?), pH, and electrical conductivity (EC; dS m?1). Root length density (cm cm?3), root mass density (mg cm?3), total dry weight, and salt-tolerance indexes were significantly reduced as a result of application of salinity. The results presented support evidence on the positive relationship between Orobance tolerance and salt tolerance in the three cultivars (Giza 429, Giza 843, and Misr 1). This adaptation was mainly due to a high degree of accumulation of inorganic nitrogen (N), phosphorus (P), K+, Ca2+, and Mg2+ and lesser quantities of Na+ and Cl?, as well as greater K+/Na+ and Ca2+/Na+ ratios.  相似文献   

9.
A laboratory incubation experiment was conducted to evaluate the effect of magnesium chloride–induced salinity on carbon dioxide (CO2) evolution and nitrogen (N) mineralization in a silty loam nonsaline alkaline soil. Magnesium chloride (MgCl2) salinity was induced at 0, 4, 8, 12, 16, 20, 30, and 40.0 dS m?1 and measured CO2 evolution and N mineralization during 30 days of incubation. Both CO2 evolution and N mineralization decreased significantly with increasing salinity. The cumulative CO2 evolution decreased from 235 mg kg?1 soil at electrical conductivity (EC) 0.65 dS m?1 to 11.9 mg kg?1 soil at 40 dS m?1 during 30 days of incubation. Similarly, N mineralization decreased from 185.4 mg kg?1 at EC 0.65 dS m?1 to 34.45 mg kg?1 at EC 40.0 dS m?1 during the same period. These results suggested that increasing magnesium chloride salinity from 4 dS m?1 adversely affect microbial activity in terms of carbon dioxide evolution and N mineralization.  相似文献   

10.
To determine the effects of irrigation water quality, plants were irrigated with normal potable water [0.25 dS m?1 electrical conductivity (EC), 25 mg L?1 sodium (Na), 55 mg L?1 chloride (Cl)], treated effluent (0.94 dS m?1 EC, 122 mg L?1 Na, 143 mg L?1 Cl) and saline water with low salinity (1.24 dS m?1 EC, 144 mg L?1 Na and 358 mg L?1 Cl) and high salinity (2.19 dS m?1 EC, 264 mg L ?1Na and 662 mg L?1 Cl) for snow peas, and high salinity (3.07 dS m?1 EC, 383 mg L?1 Na and 965 mg L?1 Cl) and very high salinity (5.83 dS m?1 EC, 741 mg L?1 Na and 1876 mg L?1 Cl) for celery. The greater salts build up in the soil and ion toxicity (Cl and Na) with saline water irrigation contributed to significantly greater reduction in root and shoot biomass, water use, yield and water productivity (yield kg kL?1 of water used) of snow peas and celery compared with treated effluent and potable water irrigation. There was 8%, 56% and 74% reduction in celery yield respectively with treated effluent, high salinity and very high salinity saline water irrigation compared with potable water irrigation. The Na concentration in snow peas shoots increased by 54%, 234% and 501% with treated effluent, low and high salinity saline water irrigation. Similarly, the increases in Na concentration in celery shoots were 19%, 35% and 82%. The treated effluent irrigation also resulted in a significant increase in soil EC, nitrogen (N) and phosphorus (P) content compared with potable water irrigation. The heavy metals besides salts build up appears to have contributed to yield reductions with treated effluent irrigation. The study reveals strong implications for the use of saline water and treated effluent for irrigation of snow peas and celery. The salt build up within the root zone and soil environment would be critical in the long-run with the use of saline water and treated effluent for irrigation of crops. To minimize the salinity level in rhizosphere, an alternate irrigation of potable water with treated effluent or low salinity level water may be better option.  相似文献   

11.
Using leaching to remove salt beyond the root zone by deep percolation requires more water to be added and this increases the stress on water resources. We hypothesized that biochar addition could mitigate salt stresses on plants and reduce the leaching fraction. For this purpose, seven irrigation water salinity levels with electrical conductivities of 1, 2, 4, 5, 6, and 7.0 dS m???-1 and tap water (0.75 dS m?1) as a control treatment coupled with three biochar applications at rates of 0% (B0), 5% (B1), and 10% (B2) were used in a randomized design with three replications. Irrigation practices were realized by considering the weight of each pot. The results revealed that the actual evapotranspiration (AET) values ranged from 30.56 to 13.83 L pot?1 for the S0B2 and B0S6 treatments. Also, the results revealed that the total water applied (TWA) for salt leaching decreased following the applications of biochar and increased with increase of? electrical conductivity. The analysis of variance showed significant differences among actual yield (AY), leaching yield (LY), and simulated yield (SY) under biochar addition and irrigation treatments. For B0, the greatest fruit yield (219.4 g pot?1) was obtained from the S0 under LY. Similar results were obtained for B1 and B2 under S0 in LY with maximum fruit yield of 250.7 and 277.7 g plant?1, respectively. Realized leaching fractions under non-biochar ranged from 5% to 78% whereas for B1 they ranged from 4% to 58%, while for B2 they ranged from 3% to 32%. Results of the water-use efficiency (WUE) showed that the lowest WUE0 and WUE1 (0.00 and 5.53 g L?1) were obtained under B0S6 whereas the highest values (7.93 and 11.1 g L?1) were observed under B2S0. Moreover, we found that biochar mitigated salinity stress in Okra by capturing transient sodium ions and reducing ion toxicity, which are preferentially absorbed onto the biochar surfaces, while releasing potassium, calcium, and magnesium ions from biochar into the soil solution.  相似文献   

12.
The present study was conducted to assess the effect of soil salinity on yield attributes as well as nutrient accumulation in different plant parts of seven Brassica cultivars from two different species raised in pot culture experiment with two levels of salinity treatments along with control corresponding to soil electrical conductivity (EC) values of 1.65 (S0), 4.50 (S1) and 6.76 (S2) dS m?1. The experiment was consisted of twelve replications in a completely randomized design. Imposition of salinity stress affected various yield attributing characters including plant height, which ultimately led to severe yield reduction. However, tolerant cultivars, CS 52 and CS 54 performed better under salt treatment showing lesser yield loss. Salinity stress reduced the nitrogen (N) content in leaves of the Brassica plants, which reflected in decreased seed protein content. Reduced accumulation of iron (Fe), manganese (Mn) and zinc (Zn) was observed in leaf, stem and root at flowering and post-flowering stages, while CS 52 and CS 54 showed less reduction than susceptible cultivars under salinity stress.  相似文献   

13.
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14.
Introducing autumn-sown legumes into Central European farming systems could be beneficial for addressing two challenges for European agriculture, i.e., the substantial deficit of protein sources for livestock and expected changes in agroclimatic conditions. Therefore, a two-year field experiment was conucted under Pannonian climate conditions in eastern Austria to assess nitrogen (N) yield and N fixation of several winter faba bean varieties from different European countries as compared to a spring faba bean. Winter wheat was used as a reference crop for estimating atmospheric N fixation. Winter faba beans were susceptible to frost damage especially in the harder of the two winters. Winter faba bean varieties could not achieve a higher grain yield and a higher grain N yield than the spring faba bean but had a higher grain N concentration (except for one variety). Grain yield and grain N yield of faba beans were severely impaired by drought in one year (with a mean of varieties of 8.3 g N m?2, winter wheat: 6.4 g N m?2); in the other year, grain N yield of faba beans considerably surpassed that of winter wheat (with a mean of varieties of 21.5 g N m?2, winter wheat: 8.8 g N m?2). After harvest, faba beans left higher nitrate residues in the soil, especially in the subsoil, and higher amounts of N in above-ground residues compared to winter wheat. Faba beans showed high N fixation under optimum conditions (with a mean of varieties of 21.9 g N m?2) whereas drought considerably impaired N fixation (with a mean of varieties of 6.3 g N m?2; with no differences between autumn- and spring-sown faba beans). In conclusion, growing winter faba bean varieties in eastern Austria did not result in higher grain yield, grain N yield, and N fixation compared to growing a spring faba bean.  相似文献   

15.
Salt-affected soils are widespread, particularly in arid climates, but information on nutrient dynamics and carbon dioxide (CO2) efflux from salt-affected soils is scarce. Four laboratory incubation experiments were conducted with three soils. To determine the influence of calcium carbonate (CaCO3) on respiration in saline and non-saline soils, a loamy sand (6.3% clay) was left unamended or amended with NaCl to obtain an electrical conductivity (EC) of 1.0 dS?m?1 in a 1:5 soil/water extract. Powdered CaCO3 at rates of 0%, 0.5%, 1.0%, 2.5%, 5.0% and 10.0% (w/w) and 0.25-2 mm mature wheat residue at 0% and 2% (w/w) were then added. Cumulative CO2-C emission from the salt amended and unamended soils was not affected by CaCO3 addition. To investigate the effect of EC on microbial activity, soil respiration was measured after amending a sandy loam (18.8% clay) and a silt loam (22.5% clay) with varying amount of NaCl to obtain an EC1:5 of 1.0–8.0 dS?m?1 and 2.5 g glucose C?kg?1 soil. Soil respiration was reduced by more than 50% at EC1:5?≥?5.0 dS?m?1. In a further experiment, salinity up to an EC1:5 of 5.0 dS?m?1 was developed in the silt loam with NaCl or CaCl2. No differences in respiration at a given EC were obtained between the two salts, indicating that Na and Ca did not differ in toxicity to microbial activity. The effect of different addition rates (0.25–2.0%) of mature wheat residue on the response of respiration to salinity was investigated by adding NaCl to the silt loam to obtain an EC1:5 of 2.0 and 4.0 dS?m?1. The clearest difference between salinity levels was with 2% residue rate. At a given salinity level, the modelled decomposition constant ‘k’ increased with increasing residue addition rate up to 1% and then remained constant. Particulate organic carbon left after decomposition from the added wheat residues was negatively correlated with cumulative respiration but positively correlated with EC. Inorganic N (NH 4 + -N and NO 3 ? -N) and resin P significantly decreased with increasing salinity. Resin P was significantly decreased by addition of CaCl2 and CaCO3.  相似文献   

16.
ABSTRACT

Soil salinity is a major abiotic factor limiting crop production but an amendment with synthetic zeolite may mitigate effects of salinity stress on plants. The objective of the study was to determine the effects of zeolite on soil properties and growth of barley irrigated with diluted seawater. Barley was raised on a sand dune soil treated with calcium type zeolite at the rate of 1 and 5% and irrigated every alternate day with seawater diluted to electrical conductivity (EC) levels of 3 and 16 dS m?1. Irrigation with 16 dS m?1 saline water significantly suppressed plant height by 25%, leaf area by 44% and dry weight by 60%. However, a substantial increase in plant biomass of salt stressed barley was observed in zeolite-amended treatments. The application of zeolite also enhanced water and salt holding capacity of soil. Post-harvest soil analysis showed high concentrations of calcium (Ca2 +), magnesium (Mg2 +), sodium (Na+), and potassium (K+) due to saline water especially in the upper soil layer but concentrations were lower in soils treated with zeolite. Zeolite application at 5% increased Ca2 + concentration in salt stressed plants; concentrations of trace elements were also increased by 19% for iron (Fe2 +) and 10% for manganese (Mn2 +). The overall results indicated that soil amendment with zeolite could effectively ameliorate salinity stress and improve nutrient balance in a sandy soil.  相似文献   

17.
Leguminous crops are significantly involved in the global symbiotic biological N2 Fixation (BNF), an eco‐friendly process in the agriculture system. Biochar is considered as a vital amendment in improving growth and quality of crops and soils. Few investigations have been conducted to determine the combination effect of biochar with microelements on growth of legumes and soil properties. This study was designed to study the effect of soybean straw‐derived biochar (SSDB) with or without microelements on soil microbial and chemical properties, growth, yield, and seed chemical composition of faba bean (Vicia faba L.). Results revealed that dehydrogenase (DHA) and phosphatase (P‐ase) activities were markedly improved with the increase of SSDB rates under addition of microelements and their highest values were recorded after 90 d. Significant increases were noticed in nodulation activities, nodulation numbers (30.1–72.8), concentrations of N (1.62–1.93%), P (0.15–0.21%), and K (0.53–0.67%), and seed chemical constituents due to the addition of SSDB in the presence of microelements. Moreover, the combination of biochar with microelements caused significant changes in microbial counts. Overall, this investigation shows the potential and role of SSDB in enhancing the growth quality of faba bean seeds as well as an improvement of soil characteristics.  相似文献   

18.
Reforestation of saline sodic soil is increasingly undertaken as a means of reclaiming otherwise unproductive agricultural land. Currently, restoration of degraded land is limited to species with high tolerances of salinity. Biochar application has the potential to improve physical, biological and chemical properties of these soils to allow establishment of a wider range of plants. In a glasshouse trial, we applied biochar made from Acacia pycnantha (5 Mg ha−1) or no biochar to either a low (ECe 4·75 dS m−1, ESP 6·9), a moderate (ECe 27·6 dS m−1, ESP 29·3) or a high (ECe 49·4 dS m−1, ESP 45·1) saline sodic soil. The regional common reforestation species Eucalyptus viminalis and Acacia mearnsii were planted as tubestock in to the soils. Early establishment indicators, including growth, plant condition and nutrition, were assessed at the end of a simulated growing season, 108 days after biochar application. Application of biochar increased height, and decreased root : shoot and the concentration of Mn, N and S in plants of E. viminalis when grown in the highly saline sodic soil. Biochar application increased the concentration of B in leaves of E. viminalis and increased the concentration of P, K and S in leaves of A. mearnsii when grown in the low saline sodic soil. The results confirm that there is potential for biochar to assist in reforestation of saline sodic soils. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

19.
A greenhouse experiment was conducted in the Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi (U.P.), India, during kharif 2013 to find out the effect of biochar and sewage sludge (SS) on growth, yield, and micronutrient uptake in rice crop. Nine treatments were employed using six different doses of biochar (2.5, 5.0, 7.5 10, 15, and 20 t ha?1) amended with a fixed dose of SS (30 t ha?1) and 50% recommended dose of nitrogen (50% RDN), i.e., 60 kg ha?1. Other three treatments were absolute control (no fertilizers), 100% recommended dose of fertilizers (100% RDF) which was 120:60:60 kg ha?1 as nitrogen (N): phosphorus pentoxide (P2O5):dipotassium oxide (K2O), and 30 t ha?1SS + 50% RDN. Experimental results showed a significant increase in yield of rice crop with increasing levels of biochar along with SS. Application of biochar at 20 t ha?1 along with 30 t ha?1SS increased grain yield to the extent of 2.5 times over absolute control (no fertilizers) and 8.5% over control (100% RDF). The uptake of iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) (micronutrients) increased significantly with graded doses of biochar application from 2.5 to 20 t ha?1 in the soil. The maximum micronutrient uptake and grain yield of rice were found in T9 where 30 t ha?1SS along with 20 t ha?1 biochar was applied with only 50% RDN. The maximum availability of micronutrients in soil was found with 30 t ha?1 of SS + 50% RDN (T3) followed by conjoint application of 20 t ha?1 of biochar and 30 t ha?1 SS + 50% RDN (T9).  相似文献   

20.
For understanding the effects of soil salinity and nitrogen (N) fertilizer on the emergence rate, yield, and nitrogen-use efficiency (NUE) of sunflowers, complete block design studies were conducted in Hetao Irrigation District, China. Four levels of soil salinity (electrical conductivity [ECe] = 2.44–29.23 dS m?1) and three levels of N fertilization (90–180 kg ha?1) were applied to thirty-six microplots. Soil salinity significantly affected sunflower growth (P < 0.05). High salinity (ECe = 9.03–18.06 dS m?1) reduced emergence rate by 24.5 percent, seed yield by 31.0 percent, hundred-kernel weight by 15.2 percent, and biological yield by 27.4 percent, but it increased the harvest index by 0.9 percent relative to low salinity (ECe = 2.44–4.44 dS m?1). Application of N fertilizer alleviated some of the adverse effects of salinity, especially in highly saline soils. We suggest that moderate (135 kg ha?1) and high (180 kg ha?1) levels of N fertilization could provide the maximum benefit in low- to moderate-salinity and high- or severe-salinity fields, respectively, in Hetao Irrigation District and similar sunflower-growing areas.  相似文献   

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