Neetu Sharma

Biochar A Source of C Sink and Soil Health-A Review

Biochar refer to the carbon-rich materials (charcoal) obtained from the thermo-chemical conversion of biomass in an oxygen‐ limited environment (pyrolysis). Biochar was first found in the Central Amazon basin. Applying biochar to agricultural soils is considered to improve carbon sequestration and decreased greenhouse gas emissions from agriculture. Recently, biochar has gotten attention of researchers because of its capacity to improve water-holding capacity and nutrient-holding ability of soil because of its porous structure, high specific surface area, and CEC. Use of biochar can increase soil nutrient availability in the long term (Lehmann et al., 2003; Rondon et al., 2007; Steiner et al., 2008). The use of biochar can enhance soil pH and soil CEC (Liang et al., 2006) and increase in soil water retention capacity and decrease in soil strength (Chan et al., 2007). Adoption of biochar management does not require new resources but makes use of locally available and renewable materials in a sustainable way. Biomass can include forestry and agricultural waste products, municipal green waste, biosolids, animal manures, some industrial wastes such as peppermill wastes. Soil organic matter is the key to soil health. In wet tropical condition, organic matter is easily subjected to decomposition and mineralization. Mineralization produces CO2 in just a few seasons and causes nutrient content to be low. International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 04 (2018) Journal homepage: http://www.ijcmas.com

Tillage and weed management on yield and nutrient uptake of wheat under maize-wheat cropping system in Western Himalayas

A field experiment was conducted during Rabi season of 2013–14 and 2014–15 at SKUAST-Jammu to study the effect of tillage and weed management on yield and nutrient uptake of wheat under maizewheat cropping system in sub-tropical irrigated conditions. The results revealed that different tillage systems recorded non-significant grain yield of wheat. However, ZT in wheat either preceded by conventional tillage (CT) or zero tillage (ZT) in maize was more beneficial as it recorded higher net returns and benefit: cost ratio than CT in wheat. Among the weed management, post-emergence application of metribuzin at 200 g/ha resulted in lowest total weed density and biomass of weeds, which was statistically at par with two hand weedings and significantly lower than weedy check. The postemergence application of metribuzin at 200 g/ha also recorded highest weed control efficiency (WCE), net returns and B: C ratio during both the years of experimentation followed by two hand weedings.

Sowing time and weed management to enhance productivity of direct-seeded aromatic rice

Field experiments were conducted during Kharif 2012 and 2013 sandy clay loam soil to study the effect of times of planting and weed management in direct-seeded aromatic rice in foot hills J&K Himalayas. Results revealed that direct-seeded basmati rice sown on 15th June and 10th July recorded non-significant results with respect to grain and straw yield. Among herbicidal weed management, post-emergence application of bispyribac at 30 g/ha recorded significantly higher grain and straw yield which was at par with post-emergence application of cyhalofop-butyl + 2, 4-D 90 g/ha + 500 g/ha and anilophos + ethoxysulfuron at 375 g/ha + 15 g/ha with B: C ratio of 2.98 and 3.95 during Kharif 2012 and 2013, respectivly. It was owing to higher number of panicles/m2, grains/panicle and 1000-grain weight along with lowest weed density, weed dry matter, higher weed control efficiency and lowest weed index.

Increase in yield of winter maize + potato intercropping system by weed management

A field experiment consisted of four intercropping systems, viz. winter maize (sole), potato (sole), winter maize + potato (additive series) and winter maize + potato (replacement series) and six sub-plot treatments comprised of weedy check, weed free, alachlor as pre-emergence at1.5 kg/ha, atrazine as preemergence at 0.5 kg/ha, early post-emergence alachlor at 2.0 kg/ha and atrazine as post-emergence at 0.75 kg/ha was laid out in split plot design with three replications. Results revealed that Medicago sativa, Anagallis arvensis and Cyperus rotundus recorded highest relative weed density and dry weed weight. The values of weed smothering efficiency were numerically higher in additive as compared to replacement treatment. Maximum yield loss was in weedy check in comparison to weed-free plots. Preemergence application of atrazine 0.5 kg/ha resulted in significantly lower dry-matter accumulation of all the weed species and highest weed-control efficiency which lead to significantly higher crop productivity.