Extreme nature of climate and topographical conditions may affect soil properties at cold desert high altitude. Hence, the present investigation was undertaken to know altitudinal variations in soil physico-chemical properties at cold desert high altitude region. For this, agriculture soils were collected from different altitude viz. site I (10000-11000 ft), site II (11000-12000 ft) and site III (>12000 ft amsl) at Leh-Ladakh (cold desert high altitude region), India. Interestingly, sand percentage in soil was significantly high at site III and decreased gradually with the altitude. In contrast to sand level, silt concentration was high at site I and decreased significantly (p<0.05) with increasing altitude. There was no significant (p<0.05) difference in bulk density (BD) and electrical conductivity (EC) among all study sites. However, the highest pH, total dissolved solid (TDS), and CaCO 3 value was recorded at site I while higher soil organic matter (SOM) was at site III. Pearson correlation coefficient analysis showed the negative correlation (p<0.01, p<0.05) of clay, silt, and pH, whereas positive correlation of sand and SOM (p<0.01) with altitude. Hence, our findings suggest the altitudinal variations in soil physico-chemical properties at cold desert high altitude.

Graphical abstract

To enhance productivity, alleviate environmental and management constraints, and enhance farmers’ incomes in the rice–wheat cropping system of the Indo Gangetic Plains, new approaches that are labour-saving, more productive and sustainable need to be developed. Most systems of rice cultivation use puddling to prepare the seedbed and control weeds in rice fields of rainfed, stress-prone environments. This practice might be helpful to reduce weed pressure and obtain slightly higher productivity, but might have negative impacts on soil physical properties. A better understanding is needed of the comparative advantage of unpuddled rice fields for maintaining good soil physical properties. To study the effect of different rice establishment methods on soil physical properties in a rice–wheat cropping system, we analysed soil samples in 2 years (2012–13 and 2013–14) from an experiment testing puddled and unpuddled rice-establishment methods. The treatments were: (i) puddled, transplanted with best management practices; (ii) puddled, transplanted with the system of rice intensification; (iii) unpuddled, transplanted; and (iv) unpuddled, direct-seeded. Omission of puddling improved soil physical properties such as bulk density, penetration resistance, aggregation stability and cracking behaviour. The absence of soil disturbance also improved soil aggregation, average mean-weight diameter and water-stable aggregates. Thus, unpuddled conditions increased the macro-aggregate fraction by 18–33%. By contrast, the higher frequency of smaller macro-aggregates (0.053–0.25 mm diameter) in puddled conditions clearly indicated the breakdown of larger macro-aggregates (>0.25 mm) into smaller size fractions. Puddled treatments were also characterised by a hard pan and wider, longer and deeper cracks, with a crack volume more than three times higher in puddled conditions. Unpuddled treatments recorded slightly higher nutrient contents in the topsoil. The study reveals that puddling deteriorates soil health. However, a long-term study is required for a better understanding of the soil changes related to different rice establishment technologies.

AbstractsTo produce anticipated output of any crop, the site specific nutrients management (SSNM) is essential for balance and adequate nutrients supply without impairing the inherent fertility status of soil. For cowpea seed production and to maintain soil nutrient status, a field experiment was conducted with nine treatments (nutrients combinations) to find out appropriate SSNM practice. Nutrients especially N, P, K, S, Zn and Bo requirement for cowpea seed production was estimated to 30, 60, 50, 30, 15 and 2.0 kg per hectare respectively and treated as 100% of SSNM. Growth and development parameters were significantly influenced with the treatments. Maximum plant height (61.9 cm) was recorded when crop was fed with 125 per cent of SSNM. However minimum plant height (54.8 cm) was recorded in case of SSNM-N. Leaf Area Index (LAI) at 60 DAS ranged from 3.37 to 3.91. Nodules dry weight was significantly influenced by boron treatments apart from nitrogen and other as well. Maximum seed yield was obtained (2237.2 kg /ha) in the plot fertilized with 125 per cent of SSNM and minimum (1343.5 kg/ha) was recorded in the plot fertilized with state recommendation. Highest and lowest gross ( 40270/-and 24183/-) was recorded with 125 per cent of SSNM and with state recommendation respectively. Application of 125 per cent of SSNM recorded maximum uptake of nitrogen (205.3 kg / ha) which is at par with 100 % of SSNM. None of the treatment influences significantly soil fertility and physico-chemical properties of the soil rather slight improvement were recorded in all the observed parameters though considerable build-up of available P and exchangeable K was noticed in plots fertilized with SSNM.

BACKGROUNDNutrient deficiency in humans, especially in children and lactating women, is a major concern. Increasing the micronutrient concentration in staple crops like rice is one way to overcome this. The micronutrient content in rice, especially the iron (Fe) and zinc (Zn) content, is highly variable. The identification of rice genotypes in which there are naturally high Fe and Zn concentrations across environments is an important target towards the production of biofortified rice.RESULTSPhenotypic correlations between grain Fe and Zn content were positive and significant in all environments but a significant negative association was observed between grain yield and grain Fe and Zn. Promising breeding lines with higher Zn or Fe content, or both, were: IR 82475‐110‐2‐2‐1‐2 (Zn: 20.24–37.33 mg kg−1; Fe: 7.47–14.65 mg kg−1); IR 83294‐66‐2‐2‐3‐2 (Zn: 22–37–41.97 mg kg−1; Fe: 9.43–17.16); IR 83668‐35‐2‐2‐2 (Zn: 27.15–42.73 mg kg−1; Fe: 6.01–14.71); IR 68144‐2B‐2‐2‐3‐1‐166 (Zn: 23.53–40.30 mg kg−1; Fe: 10.53–17.80 mg kg−1) and RP Bio 5478‐185M7 (Zn: 22.60–40.07 mg kg−1; Fe: 7.64–14.73 mg kg−1). Among these, IR82475‐110‐2‐2‐1‐2 (Zn: 20.24–37.33 mg kg−1; Fe: 7.47–14.65 mg kg−1) is also high yielding with 3.75 t ha−1. Kelhrie Cha (Zn: 17.76–36.45 mg kg−1; Fe: 7.17–14.77 mg kg−1), Dzuluorhe (Zn: 17.48–39.68 mg kg−1; Fe: 7.89–19.90 mg kg−1), Nedu (Zn: 18.97–43.55 mg kg−1 Fe: 8.01–19.51 mg kg−1), Kuhusoi‐Ri‐Sareku (Zn: 17.37–44.14 mg kg−1; Fe: 8.99–14.30 mg kg−1) and Mima (Zn: 17.10–45.64 mg kg−1; Fe: 9.97–17.40 mg kg−1) were traditional donor genotypes that possessed both high grain Fe and high Zn content.CONCLUSIONSignificant genotype × location (G × L) effects were observed in all traits except Fe. Genetic variance was significant and was considerably larger than the variance of G × L for grain Zn and Fe content traits, except grain yield. The G × L × year variance component was significant in all cases. © 2020 Society of Chemical Industry