Search

Moisture stress and low soil fertility are among the most important factors responsible for low productivity and profitability of peanut (Arachis hypogaeaL.) in India. Conservation agriculture (CA) can delay or minimize moisture stress impacts on crop plants and improve the soil fertility. Hence, a field experiment was conducted at Research Farm of ICAR‐Directorate of Groundnut Research, Junagadh, during 2015–2016 and 2016–2017 to evaluate the effects of different CA practices on soil moisture, soil fertility, yield, and profitability of peanut systems. Treatments consisted of four tillage practices in main plots (conventional tillage [CT], minimum tillage [MT], zero tillage [ZT], and rotary tillage [RT]); two residue management practices in sub‐plots (residue removal [NR] and residue retention [RR]), and two intercropping systems in sub‐sub plots using peanut, pigeonpea [Cajanus cajan(L.) Millsp.], and cotton (Gossypium hirsutumL.) (peanut+pigeonpea [PP] and peanut+cotton [PC]) systems and replicated thrice. Minimum tillage and residue management practice RR improved soil moisture content, soil porosity, soil organic C, nutrient status (mainly at 0–15 cm), and soil enzymatic activities and decreased soil temperature variation and soil penetration resistance. Minimum tillage and RR resulted in higher financial returns over CT and NR, respectively. Among the cropping systems, PP was found more productive and profitable as compared to PC. Thus, in the light black soils of Saurashtra, India, MT along with RR seems to be a suitable option particularly during the initial years of shifting to CA to retain soil moisture, improve soil fertility, and provide higher financial returns.

Ashwagandha [Withania somnifera(Linn.) Dunal] is a medicinal herb with profound therapeutic uses that is facing challenges of poor quality and safety due to lack of nutrients in the soil. Organic manures (farmyard manure, vermicompost, and castor cake) and biostimulants (Azotobacter, phosphate‐solubilizing bacteria [PSB], and Jivamrut) along with a control treatment were investigated in a 2‐yr field experiment for their effects on yield and quality of ashwagandha. Application of castor cake along with the consortia of biostimulants (biofertilizers+Jivamrut) increased (p= .05) dry root yield (+36.4%) over the untreated control. Root yield was positively correlated (p= .01) with plant height, branches per plant, plant biomass, and root length and girth. Different forms of withanolides (withaferin‐A, 12‐Deoxy withastramanolide, and withanolide‐A) and total withanolide increased root yield 29% with the combined use of vermicompost and Jivamrut over the control. Plant biomass and different forms of withanolides were positively correlated (p= .01) with total withanolides content, whereas root C was correlated (p= .05) with withaferin‐A content. Vermicompost increased (p= .05) soil chemical (soil organic C [SOC], N, P, and S) and biochemical (microbial biomass C [MBC], fluorescein diacetate hydrolytic [FDH], dehydrogenase activity [DHA], and alkaline and acid phosphatase) parameters. The consortia of biostimulants (Azotobacter+PSB+Jivamrut) markedly improved SOC, N, P, MBC, FDH, DHA, and alkaline phosphatase; however, S was greatest with Jivamrut. Thus, application of either castor cake or vermicompost along with biostimulants (Azotobacter+PSB+Jivamrut) increased root yield and quality of ashwagandha and increased soil health.

Integrated use of castor cake 2.5 t and NPK 80:30:50 kg ha–1with split application of N (50% at TP and 50% in two splits at 25 and 40 DAP) produced highest dry herbage yield.Combined use of castor cake 2.5 t and NPK 80:30:50 kg ha–1(50% N at TP and 50% at 25 DAP) recor–ded highest quality in terms of andrographolide content.Increased supply of NPK either through organics or inorganics showed positive and linear increase in andrographolide content. Kalmegh (Andrographis paniculataNees) is being used since centuries in Asia as an alternative medicine to cure various health ailments. However, the quality, efficacy, and safety are major challenges due to lack of standard production protocols. A study was conducted with organic and inorganic nutrient sources, and split application of N to increase the herbage yield and quality as well, while maintaining/improving the soil fertility. Castor cake 2.5 t ha−1recorded highest plant height, branches, and plant N and K content, whereas, P content was higher with vermicompost 7.5 t ha−1. Application of NPK 80:30:50 kg ha−1with or without split application of N increased plant height and branches per plant, and plant NPK content. Interaction effects showed that combined use of castor cake 2.5 t ha−1along with NPK 80:30:50 kg ha−1and 2/3 split application of N recorded significantly higher herbage yield (8.1 t ha−1), and andrographolide content (24.2 mg g−1). Positive and linear regression [N (R2= 0.64), P (R2= 0.40) and K (R2= 0.16)], and significant correlation [N (r= 0.80) P (r= 0.63) and K (r= 0.40)] at P= 0.01 were found between NPK applied and andrographolide content in plants. Vermicompost 7.5 t ha−1and NPK 80:30:50 kg ha−1(50% N in 2–3 splits) improved soil NPK content. Thus, integrated use of castor cake 2.5 t ha−1along with NPK 80:30:50 kg ha−1(N in 2/3 split applications) found optimum to harvest maximum commercial produce of better quality and improved soil fertility.

Peanut–wheat–Sesbania cropping system recorded the highest peanut–pod equivalent yield.Peanut–wheat–Sesbania/ green gram markedly increased soil enzymatic activities.Bulk density decreased in peanut‐CTW and peanut + pigeonpea crop rotations. Peanut (Arachis hypogaeaL.) is a soil‐C depleting crop under a continuous monocropping system. A study was conducted comprising combinations of tillage practices (zero tillage [ZT] or conventional tillage [CT]), crop rotation (sole peanut, peanut‐wheat [Triticum aestivumL.], or peanut+pigeonpea [Cajanus cajanL.]), and green manuring (GM) (green gram [Vigna radiataL.], sesbania [Sesbania aculeataWilld.], or wheat straw incorporation [WSI]). Peanut pod yield was found higher in peanut followed by wheat either zero tilled (ZTW) or conventional tilled (CTW), and GM either with sesbania/green gram/WSI. Green manuring in peanut–ZTW and peanut+pigeonpea recorded higher grain yield of wheat (3.11 t ha−1) and pigeonpea (1.76 t ha−1), respectively. Sesbania GM increased root biomass of peanut, wheat, and pigeonpea in all the systems. Peanut‐pod equivalent yield recorded significantly higher in peanut–ZTW or CTW when included GM with either sesbania or green gram (3.64 t ha−1). Found higher accumulation of soil N in peanut–ZTW–sesbania (33.8 kg ha−1), P in peanut–CTW (6.4 kg ha−1), and S in peanut–CTW (3.7 kg ha−1) crop rotations. Activities of urease, β‐glucosidase, acid phosphatase, and alkaline phosphatase were increased in all the crop rotations that included green manuring or WSI over sole peanut. Soil bulk density (0–15 cm depth) was recorded lower in peanut–CTW, however, higher in peanut–ZTW. Peanut followed by ZTW or CTW and green manuring either with sesbania or green gram found more sustainable than sole peanut in terms of peanut‐pod equivalent yield and improved soil enzyme activities.

Rice (Oryza sativaL.)–wheat (Triticum aestivumL.) cropping in South Asia is under stress due to widespread removal of plant nutrients in excess of their application. We evaluated K, S, and Zn application to rice and wheat in 60 farmer’s fields in five districts across northern India. We compared the existing farmer’s fertilizer practice (FFP), which in most cases did not include application of K, S, or Zn, with application of K only, S + Zn, or K + S + Zn. Application of K increased rice yields by 0.6 to 1.2 Mg ha−1and wheat yields by 0.2 to 0.7 Mg ha−1across the locations varying in soil texture, soil K, climate, and irrigation. Application of S and Zn with K further increased yields. Added net return from fertilization with only K, as compared to FFP, ranged from U.S.$ 114 to 233 ha−1for rice and U.S.$ 29 to 214 ha−1for wheat. Added net return further increased when S and Zn were combined with K. Total plant K per unit of grain yield was comparable for mature rice and wheat (22 kg Mg grain−1). Soil exchangeable and non‐exchangeable K decreased without K application during one rice–wheat cropping cycle. Rice and wheat yields increased with application of K across the range in exchangeable soil K from 60 to 162 mg kg−1. Approaches are needed to reliably predict fertilizer K requirements when crops respond relatively uniformly to K across a wide range in exchangeable K.

A better understanding of the growth response of rice (Oryza sativaL.) to waterlogged soil conditions is desirable. The objective of this study was to measure the influence of soil water regime on root porosity, growth, and nutrient content of four varieties of rice at various dates after transplanting. Four rice varieties (‘IR8’, ‘Padma’, ‘BC6’, and ‘IR22’) were grown under three soil water regimes (continuous flooding, alternate flooding, and no flooding) in a greenhouse on a clay loam soil. Root porosity, growth of plants and nutrient (N, P, K, Ca, and Mg) content of shoots were determined at four different plant ages (30, 60, 85, and 110 days after transplanting). Root porosity was greatest in plants grown with continuous flooding. Porosity of roots in all four varieties reached maximum values between 30 and 60 days and then started to decline. Padma and BC6 had higher root porosities than IR8 and IR22. High root porosity was associated with greater root length, increased dry weight of roots and shoots, and higher nutrient content in shoots.

Maize (Zea maysL.) plants were grown in furrows and ridges in a lowlying sandy clay loam soil under high soil‐water conditions. Root porosities of 44‐day‐old plants were studied. The investigation was undertaken to determine varieties that could adjust to such environment through internal aeration. Varietal differences were found in the percentage of air space of roots. Plants grown in furrows had higher root porosities than those grown in ridges. Six varieties studied were ‘Kissan,’ ‘Deccan,’ ‘Jawahar,’ ‘Ganga 5,’ ‘Vikram,’ and ‘Sona.’ The first two may adjust better to excess soil water due to greater internal aeration resulting from increased root porosities.