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11.
Girish Chander Suhas P. Wani Kanwar L. Sahrawat Prasad J. Kamdi Chitendra K. Pal Dilip K. Pal 《Archives of Agronomy and Soil Science》2013,59(12):1643-1658
Soil degradation in the semi-arid tropics (SAT) is mainly responsible for low crop and water productivity. In Madhya Pradesh and Rajasthan states in India, the soil analyses of farmers’ fields revealed widespread deficiencies of S (9–96%), B (17–100%) and Zn (22–97%) along with that of P (25–92%). Soil organic C was deficient in 7–84% fields indicating specifically N deficiencies and poor soil health in general. During on-farm evaluations in rainy seasons 2010 and 2011, the soil test based addition of deficient nutrient fertilizers as balanced nutrition (BN) increased crop yields by 6–40% (benefit to cost ratios of 0.81–4.28) through enhanced rainwater use efficiency. The integrated nutrient management (INM), however, decreased the use of chemical fertilizers in BN by up to 50% through on-farm produced vermicompost and recorded yields at par or more than BN with far better benefit to cost ratios (2.26–10.2). Soybean grain S and Zn contents improved with INM. Applied S, B, Zn and vermicompost showed residual benefits as increased crop yields for succeeding three seasons. Hence, results showed INM/BN was economically beneficial for producing more food, while leading to resilience building of SAT production systems. 相似文献
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R. Velmurugan P. P. Mahendran S. P. Wani K. Uttam M. Prabhavathi 《Soil Science and Plant Nutrition》2013,59(2):229-236
Abstract The decay of rice residue was investigated after incubation periods of from 1 to 24 months at 30°C under both flooded and upland soil conditions. Tops and roots of rice plants were cut into about 10-mm length, and separately incorporated in soil which had been passed through a 0.5-mm sieve. Plant debris were fractionated physically according to their sizes and divided into five groups (>4 mm, 4-2 mm, 2-1 mm, 1-0.5 mm, and 0.5-0.25 mm). Carbon loss from the soils amended with rice residues and decrease in the weight of total plant debris proceeded at a rapid speed in the early periods (around 4 months) and then at a slow speed in the subsequent periods under both flooded and uplana soil conditions. The distribution of the plant debris in the decomposition processes differed under flooded and upland conditions. Under flooded conditions, 2–4 mm-sized plant debris were retained for a long period with slow transformation into the smaller fractions. In contrast, under upland conditions, change of plant debris from large to small size fractions proceeded gradually. This continuous change could be attributed to the high decomposing activities of fungi under upland conditions. 相似文献
13.
Abstract. This study was undertaken to test the hypothesis that an improved system of catchment management in combination with appropriate cropping practices can sustain increased crop production and improve soil quality of Vertisols, compared with prevailing traditional farming practices. Initiated in 1976, the improved system consisted of integrated land management to conserve soil and water, with excess rainwater being removed in a controlled manner. This was combined with improved crop rotation (legume based) and integrated nutrient management. In the traditional system, sorghum or chickpea was grown in the post-rainy season with organic fertilizers, and in the rainy season the field was maintained as a cultivated fallow. The average grain yield of the improved system over 24 years was 4.7 t ha−1 yr−1 , nearly a five-fold increase over the traditional system (about 1 t ha−1 yr−1 ). There was also evidence of increased organic C, total N and P, available N, P and K, microbial biomass C and N in the soil of the improved system. A positive relationship between soil available P and soil organic C suggested that application of P to Vertisols increased carbon sequestration by 7.4 t C ha−1 and, in turn, the productivity of the legume-based system, thus ultimately enhancing soil quality. 相似文献
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15.
Wani Shakil A. Farooq S. Kashoo Z. A. Hussain I. Bhat M. A. Rather M. A. Aalamgeer S. 《Tropical animal health and production》2019,51(5):1089-1095
The aim of this study was to determine the prevalence, serological diversity, and virulence of Dichelobacter nodosus in footrot lesions of sheep and identification of its predominant serotype as a potential vaccine candidate. The overall prevalence of footrot in sheep was 16.19%, and ranged from 13.69 to 19.71%, respectively. A total of 759 flocks with 22,698 sheep were investigated for footrot and 2374 clinical samples were collected from naturally infected sheep exhibiting footrot lesions. Of the 2374 samples collected, 1446 (60.90%) were positive for D. nodosus by polymerase chain reaction (PCR). These positive samples when subjected to serogroup-specific multiplex PCR, 1337 (92.46%) samples carried serogroup B, 247 (17.08%) possessed serogroup E, 86 (5.94%) serogroup I, and one (0.069%) serogroup G of D. nodosus. While mixed infection of serogroups B and E was detected in 127 (8.78%), B and I in 46 (3.18%) and B, E, and I in 26 (1.79%) samples, respectively. The serogroup B of D. nodosus was the predominant (92.47%) serogroup affecting sheep population with footrot followed by serogroup E (19.91%) and serogroup I (4.57%), respectively. Virulent status of D. nodosus strains were confirmed by presence of virulence-specific integrase A (intA) gene and the production of thermostable proteases. The intA gene was detected in 709 (72.79%) samples while gelatin gel test carried out on 246 representative isolates all positive for intA gene produced thermostable proteases, confirming their virulence nature. The PCR-restriction fragment length polymorphism (PCR-RFLP) of whole fimA gene of serogroup B revealed the predominance of serotype B5 (82.97%) of serogroup B. This information suggests that serotype B5 is the predominant serotype of D. nodosus associated with severe footrot lesions in sheep in Jammu & Kashmir (J&K), India. Hence, this serotype can be a potential vaccine candidate for the effective control and treatment of ovine footrot.
相似文献16.
V. S. Bhatia P. Singh A. V. R. Kesava Rao K. Srinivas & S. P. Wani 《Journal of Agronomy and Crop Science》2009,195(6):455-463
To assess the scope for enhancing productivity of groundnut (Arachis hypogaea L.) in India, well‐calibrated and validated CROPGRO‐Peanut model was used to assess potential yields (water non‐limiting and water limiting) and yield gaps of groundnut for 18 locations representing major groundnut growing regions of India. The average simulated water non‐limiting pod yield of groundnut for the locations was 5440 kg ha?1, whereas the water limiting yield was 2750 kg ha?1 indicating a 49 % reduction in yield because of deficit soil moisture conditions. As against this, the actual pod yields of the locations averaged 1020 kg ha?1, which was 4420 and 1730 kg ha?1 less than the simulated water non‐limiting and water limiting yields, respectively. Across locations, the simulated water non‐limiting yields were less variable than water limited and actual yields, and strongly correlated with solar radiation during the crop season (R2 = 0.62, P ≤ 0.01). Simulated water limiting yield showed a significant positive, but curvilinear relationship (R2 = 0.73, P ≤ 0.01) with mean crop season rainfall across locations. The relationship between actual yield and the mean crop season rainfall across locations was not significant, whereas across seasons for some of the locations, the association was found to be significant. Total yield gap (water non‐limiting minus actual yields) ranged from 3100 to 5570 kg ha?1, and remained more or less unaffected by the quantity of rainfall received across locations. The gap between simulated water non‐limiting and water limiting yields, which ranged from 710 to 5430 kg ha?1, was large at locations with low crop season rainfall, and narrowed down at locations with increasing quantum of crop season rainfall. On the other hand, the gap between simulated water limiting yield and actual farmers yield ranged from 0 to 3150 kg ha?1. It was narrow at locations with low crop season rainfall and increased considerably at locations with increasing amounts of rainfall indicating that type of interventions to abridge the yield gap will vary with the rainfall regimes. It is suggested that improved agronomic management (such as high yielding cultivars, balance crop nutrition and control of pest and diseases) in high rainfall regimes and rainfall conservation and supplemental irrigations in low rainfall regimes will be essential components of the improved technologies aimed at abridging the yield gaps of groundnut. 相似文献
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Wani SA Hussain I Fayaz I Mir MA Nishikawa Y 《Veterinary journal (London, England : 1997)》2009,182(3):489-490
Seventy-five Escherichia coli isolates with at least one targeted virulence gene were recovered from 338 lambs with (n=230) and without (n=108) diarrhoea. The isolates belonged to 36 different serogroups. Shiga toxin-producing E. coli (STEC) was isolated from 9.6% of lambs with and 24.1% of lambs without diarrhoea. Enteropathogenic E. coli (EPEC) was isolated from 6.1% of lambs with and 11.1% of lambs without diarrhoea. Of 26 EPEC isolates, seven were typical (positive for bfpA), and, of 34 stx(1) positive isolates, 25 were subtyped as stx(1c). Five of 29 stx(2) positive isolates were subtyped as stx(2d) and two as stx(2c). Seven of 45 eae positive isolates were subtyped as eae subtype zeta (eaezeta). This appears to be the first report of the isolation of typical EPEC from sheep in India. 相似文献
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Summary In a series of short-term experiments root systems of young sorghum and millet plants inoculated with N2-fixing bacteria were exposed to 15N2-enriched atmospheres for 72 h. The plants were grown in a normal atmosphere for up to 22 days after the end of the exposure to allow them to take up the fixed N2. Environmental conditions and genotypes of sorghum and millet were selected to maximise N2-fixation in the rhizosphere. Detectable amounts of fixed N (> 16 g/plant) were rapidly incorporated into sorghum plants grown in a sand/farmyard manure medium, but measurable fixation was found on only one occasion in plants grown in soil. N2 fixation was detectable in some experiments with soil-grown millet plants but the amounts were small (2–4 g/plant) and represented less than 1 % of plant N accumulated over the same period. In many cases there was no detectable 15N2 incorporation despite measurable increases in ethylene concentration found during an acetylene reduction assay.Published as ICRISAT Journal Article No. JA 740 相似文献
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Summary This paper presents soil biological data from a study on the functioning of three soil-plant systems on a Gray Luvisol in Cryoboreal Subhumid central Alberta. The systems were (1) an agroecological 8-year rotation, (2) a continuous grain system, both established in 1981, and (3) a classical Breton 5-year rotation established in 1930. The objectives were to (1) determine whether changes in vesicular-arbuscular mycorrhizae (VAM) populations occurred in soil under these cropping systems, (2) discover whether these cropping systems and/or VAM infection influenced the incidence of common root rot (Bipolaris sorokiniana), and (3) use nutrient translocation indices to test the hypothesis that soil quality influences non-specific physiological conditions in barley (Hordeum vulgare L.). VAM fungal propagules in soil samples and VAM infection under controlled conditions were significantly affected by the cropping system. VAM infection accounted for more than 85% of the variability in grain yield, plant biomass yield, and plant uptake of K, S, Ca, Fe, and Zn under controlled conditions. Backward-elimination regression analyses showed that under these conditions of high available P, plant P uptake was governed by the quantity of extractable P in the soil (r
2=0.82); the VAM infection contributed practically nothing when combined with available P (R
2=0.84). Neither VAM infection nor the cropping system were related to the B. sorokiniana infection in the barley. The growth of B. sorokiniana was equal, and its sporulation superior, when grown on residues of the non-host fababean (Vicia faba L.), compared with growth on residues of barley. Higher translocation of plant nutrients to the grain in the agroecological compared with the continuous grain treatments suggested that VAM and/or the soil history affected plant physiology, possible through hormonal effects. Superior barley yields in the agroecological compared with the continuous grain treatments were partly due to increased VAM colonization, greater nutrient accumulation and translocation to the grain, but not to a reduced disease incidence. These results demonstrate the benefits of a holistic systems approach while studying biological interactions involving plants and groups of soil microorganisms.(ICRISAT journal article number 1161) 相似文献
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Shabir A. Bangroo Nayar A. Kirmani Mohammad A. Bhat Javaid A. Wani Asif M. Iqbal Zahoor A. Dar Syed Sheraz Mahdi Ajaz A. Malik 《植物养料与土壤学杂志》2021,184(1):112-122
Background : Potassium (K) availability in soil and plant uptake is restrained by the dynamic interactions among the different pools of K. Aims : To understand these interactions, a study was undertaken to assess the quantity–intensity (Q/I) and buffering characteristics of rainfed maize (Zea mays L.) growing soils. Ten contrasting soils were evaluated for K partitioning changes in exchangeable K (ΔEK) and non‐exchangeable K (ΔNEK) pools in the soil‐solution phase and buffering characteristics using a modified version of Q/I approach. Results : The partitioned Q/I isotherms showed strong adsorption with the increase in K concentration ratio (CRK) and the changes due to ΔEK were higher than changes due to ΔNEK. Total buffering capacity (PBCK) significantly correlated (r = 0.92, p <0.01) with clay content with a major share contributed by buffering capacity owing to non‐exchangeable K ( ) rather than exchangeable K ( ). The fixation capacity (β) factor, the magnitude of added K converted into a non‐exchangeable pool, ranged from 41 to 63%, whereas release (α) factor, the magnitude of added K converted to the exchangeable pool, ranged from 19 to 36%. Both threshold solution K (CKr) and threshold exchangeable K (EKr) values were found to be high in Satran clay loam (S2) and lower in Doon silty clay loam (S3) soils. The equilibrium exchangeable K (EKo) was found close to minimum exchangeable K (Emin) in Doon silty clay loam (S3) and Babaweyl sandy clay loam (S1) soils and overall Emin constituted about 8.94 to 0.57% of the EKo. Conclusion : It may be concluded that K Q/I isotherm partitioning provides a valuable insight to assess the dynamic relations. The ratio of α/β (K recharge index) could be used to evaluate the K enrichment capacity of soil to K additions while EKr and Emin can be potentially useful in the elucidation of exchangeable K as K fertility index especially in soils with poor K fertilizer management. 相似文献