Search

Zinc (Zn) deficiency prevails in different soils and crops of the world. Soil Zn deficiency adversely affects growth, yield and micronutrients (Zn, copper (Cu), iron (Fe) and manganese (Mn)) concentration in different crops including pigeonpea (Cajanus cajan L. Millsp.), a protein rich legume crop grown consumed in different parts of the world. Therefore, we carried out a 2-years field experiment on a Zn-deficient Vertisol with 20 different pigeonpea genotypes and 3 levels of Zn treatments in a split-plot design with 3 replications, to study the effect of Zn application on yield, micronutrients concentration and uptake by pigeonpea genotypes. The 3 levels of Zn treatments were no Zn (no Zn fertilizer was applied), soil Zn (20 kg Zn ha−1) and soil + foliar Zn. Compared to no Zn application, soil and soil + foliar application of Zn enhanced mean grain yield by 15 and 24%, stover yield by 13 and 29% and total biomass yield of pigeonpea genotypes by 13 and 29%, respectively. Soil + foliar application of Zn significantly increased mean grain Zn concentration by 33% compared to no Zn application. Soil and soil + foliar Zn application led to reduction in mean grain Cu concentration by 9 and 10%, respectively, and did not significantly increase or decrease grain Fe and Mn concentration. Soil and soil + foliar application of Zn significantly increased mean grain Zn, Fe and Mn uptake by pigeonpea genotypes compared to no Zn application. Soil + foliar application of Zn had significantly higher mean grain Zn, Fe and Mn uptake compared to soil Zn application. The grain, stover and total biomass yield, micronutrients concentration in grain and stover and micronutrients uptake by the genotypes were different under various treatments. The genotypes ICPL 87119, BDN 2, JKM 7, Virsa Arhar 1, DT 23 and AAUT 2007–10 under soil application of Zn and ICPL 87119, BDN 2, JKM 7 and Virsa Arhar 1 under soil + foliar application of Zn were found promising for cultivation to obtain higher grain yield and micronutrients uptake.

Potassium (K) is one of the essential nutrients required by crops in large quantities; however, its use in agriculture by farmers is less than required in developing countries. This neglect...

Growing areas under transgenic crops have created a concern over their possible adverse impact on the soil ecosystem. This study evaluated the effect of Bt-cotton based cropping systems on soil microbial and biochemical activities and their functional relationships with active soil carbon pools in Vertisols of central India (Nagpur, Maharastra, during 2012–2013). Culturable groups of soil microflora, enzymatic activities and active pools of soil carbon were measured under different Bt-cotton based cropping systems (e.g. cotton-soybean, cotton-redgram, cotton-wheat, cotton-vegetables and cotton-fallow). Significantly higher counts of soil heterotrophs (5.7–7.9 log cfu g−1soil), aerobic N-fixer (3.9–5.4 log cfu g−1soil) and P-solubilizer (2.5−3.0 log cfu g−1soil) were recorded in Bt-cotton soils. Similarly, soil enzymatic activities, viz. dehydrogenase (16.6–22.67 µg TPF g−1 h−1), alkaline phosphatase (240–253 µg PNP g−1 h−1) and fluorescein di-acetate hydrolysis (14.6–18.0 µg fluorescein g−1 h−1), were significantly higher under Bt-cotton-soybean system than other Bt- and non-Bt-cotton based systems in all crop growth stages. The growth stage-wise order of soil microbiological activities were: boll development > harvest > vegetative stage. Significant correlations were observed between microbiological activities and active carbon pools in the rhizosphere soil. The findings indicated no adverse effect of Bt-cotton on soil biological properties. Refereed/Peer-reviewed

Growing areas under transgenic crops have created a concern over their possible adverse impact on the soil ecosystem. This study evaluated the effect of Bt-cotton based cropping systems on soil microbial and biochemical activities and their functional relationships with active soil carbon pools in Vertisols of central India (Nagpur, Maharastra, during 2012–2013). Culturable groups of soil microflora, enzymatic activities and active pools of soil carbon were measured under different Bt-cotton based cropping systems (e.g. cotton-soybean, cotton-redgram, cotton-wheat, cotton-vegetables and cotton-fallow). Significantly higher counts of soil heterotrophs (5.7–7.9 log cfu g−1 soil), aerobic N-fixer (3.9–5.4 log cfu g−1 soil) and P-solubilizer (2.5−3.0 log cfu g−1 soil) were recorded in Bt-cotton soils. Similarly, soil enzymatic activities, viz. dehydrogenase (16.6–22.67 µg TPF g−1 h−1), alkaline phosphatase (240–253 µg PNP g−1 h−1) and fluorescein di-acetate hydrolysis (14.6–18.0 µg fluorescein g−1 h−1), were significantly higher under Bt-cotton-soybean system than other Bt- and non-Bt-cotton based systems in all crop growth stages. The growth stage-wise order of soil microbiological activities were: boll development > harvest > vegetative stage. Significant correlations were observed between microbiological activities and active carbon pools in the rhizosphere soil. The findings indicated no adverse effect of Bt-cotton on soil biological properties.

The potential of an ornamental shrub Crown of thorns (Euphorbia milli) was evaluated for remediation of soil contaminated with Cr. The plant is one of the rare succulent ornamental shrubs with a slow to moderate growth rate and is capable of blooming almost year-round. The plant could tolerate well up to 75 mg of applied Cr and beyond that there was mortality of plants. Though the plant could not be classified as a hyperaccumulator, the plant was still very efficient in translocating Cr from roots to shoots as evident from the data on uptake and translocation efficiency values. The translocation efficiency of over 80% in our study demonstrates that a large proportion of Cr has been translocated to the harvestable biomass of the plant and therefore, this plant could be effectively recommended for the remediation of soils contaminated with low to medium level of contamination i.e., up to 50 mg/kg soil.

In a field experiment, the effect of combination of different organic manures on the productivity of crops and soil quality were evaluated in deep vertisols of central India. Combinations of cattle dung manure (CDM), poultry manure (PM), and vermicompost (VC) vis-a-vis mineral fertilizers were tested in four cropping systems involving soybean (Glycine max L.), durum wheat (Triticum durum Desf.), mustard (Brassica juncea L.), chickpea (Cicer arietinum L.), and isabgol (Plantago ovata Forsk). The organic manures were applied based on the N-equivalent basis and nutrient requirement of individual crop. The grain yields of durum wheat and isabgol were higher in the treatment that received a combination of CDM + VC + PM whereas in mustard, CDM + PM and in chickpea, CDM + VC recorded the higher yields. The yield levels in these organic-manure combinations were similar to the yields obtained with mineral fertilizers. Among the cropping systems, soybean–durum wheat and among the nutrient sources, the combination of CDM + VC + PM recorded the highest total productivity. At the end of the 3-year cropping cycle, application of organic manures improved the soil-quality parameters viz., soil organic carbon (SOC), soil available nutrients (N, P, and K), soil enzymes (dehydrogenase and alkaline phosphatase), and microbial biomass C in the top 0–15 cm soil. Bulk density and mean weight diameter of the soil were not affected by the treatments. Among the cropping systems, soybean–durum wheat recorded the highest SOC and accumulated higher soil available N, P, and K. In conclusion, the study clearly demonstrated that the manures applied in different combinations improved the soil quality and produced the grain yields which are at par with mineral fertilizers.

The mineralization of sulfur (S) was investigated in a Vertisol and an Inceptisol amended with organic manures, green manures, and crop residues. Field-moist soils amended with 10 g kg -1 of organic materials were mixed with glass beads, placed in pyrex leaching tubes, leached with 0.01 M CaCl 2 to remove the mineral S and incubated at 30 °C. The leachates were collected every fortnight for 16 weeks and analyzed for SO 4 -S. The amount of S mineralized in control and in manure-amended soils was highest in the first week and decreased steadily thereafter. The total S mineralized in amended soils varied considerably depending on the type of organic materials incorporated and soil used. The cumulative amounts of S mineralized in amended soils ranged from 6.98 mg S (kg soil) -1 in Inceptisol amended with wheat straw to 34.38 mg S (kg soil) -1 in Vertisol amended with farmyard manure (FYM). Expressed as a percentage of the S added to soils, the S mineralized was higher in FYM treated soils (63.5 to 67.3 %) as compared to poultry manure amended soils (60.5 to 62.3 %). Similarly the percentage of S mineralization from subabul (Leucaena leucocephala) loppings was higher (53.6 to 55.5 %) than that from gliricidia (Gliricidia sepium) loppings (50.3 to 51.1 %). Regression analysis clearly indicated the dependence of S mineralization on the C : S ratio of the organic materials added to soil. The addition of organic amendments resulted in net immobilization of S when the C : S ratio was above 290:1 in Vertisol and 349:1 in Inceptisol. The mineralizable S pool (S o ) and first-order rate constant (k) varied considerably among the different types of organic materials added and soil. The S o values of FYM treated soils were higher than in subabul, gliricidia, and poultry manure treated soils.