• Energy Research

Food security and environmental health are directly linked with soil carbon (C). Soil C plays a crucial role in securing food and livelihood security for the Himalayan population besides maintaining the ecological balance in the Indian Himalayas. However, soil C is being severely depleted due to anthropogenic activities. It is well known that land use management strongly impacted the soil organic carbon (SOC) dynamics and also regulates the atmospheric C chemistry. Different types of cultivation practices, i.e., forest, plantations, and crops in the Kashmir Himalayas, India, has different abilities to conserve SOC and emit C in the form of carbon dioxide (CO2). Hence, five prominent land use systems (LUC) (e.g., natural forest, natural grassland, maize-field-converted from the forest, plantation, and paddy crop) of Kashmir Himalaya were evaluated to conserve SOC, reduce C emissions, improve soil properties and develop understanding SOC pools and its fractions variations under different land use management practices. The results revealed that at 0–20 cm and 20–40 cm profile, the soil under natural forest conserved the highest total organic carbon (TOC, 24.24 g kg−1 and 18.76 g kg−1), Walkley-black carbon (WBC, 18.23 g kg−1 and 14.10 g kg−1), very-labile-carbon (VLC, 8.65 g kg−1, and 6.30 g kg−1), labile-carbon (LC, 3.58 g kg−1 and 3.14 g kg−1), less-labile-carbon (VLC, 2.59 g kg−1, and 2.00 g kg−1), non-labile-carbon (NLC, 3.41 g kg−1 and 2.66 g kg-1), TOC stock (45.88 Mg ha−1 and 41.16 Mg ha−1), WBC stock (34.50 Mg ha−1 and 30.94 Mg ha−1), active carbon pools (AC, 23.14 Mg ha−1 and 20.66 Mg ha−1), passive carbon pools (PC, 11.40 Mg ha−1 and 10.26 Mg ha−1) and carbon management index (CMI, 100), followed by the natural grassland. However, the lowest C storage was reported in paddy cropland. The soils under natural forest and natural grassland systems had a greater amount of VLC, LC, LLC, and NLC fraction than other land uses at both depths. On the other hand, maize-field-converted-from-forest-land-use soils had a higher proportion of NLC fraction than paddy soils; nonetheless, the NLC pool was maximum in natural forest soil. LUS based on forest crops maintains more SOC, while agricultural crops, such as paddy and maize, tend to emit more C in the Himalayan region. Therefore, research findings suggest that SOC under the Kashmir Himalayas can be protected by adopting suitable LUS, namely forest soil protection, and by placing some areas under plantations. The areas under the rice and maize fields emit more CO2, hence, there is a need to adopt the conservation effective measure to conserve the SOC without compromising farm productivity.

Environmental pollution, resource dwindling, and soil degradation questioned the sustainability of contemporary agricultural production systems. Organic farming is advocated as a sustainable solution for ensuring food security without compromising environmental sustainability. However, poor farm productivity quizzed the sustainability of organic production systems. Hence, a field study was carried out in the Sikkim region of the Indian Himalayas to assess the efficacy of conservation-effective tilling and diversified cropping on system productivity, profitability, environmental quality, and soil nutrient balance in organic farming. Three tillage systems, namely, (i) conventional tillage (CT), (ii) reduced tillage (RT), and (iii) zero tillage (ZT), and four maize based diversified cropping systems (maize–black gram–toria, maize–black gram–buckwheat, maize–rajmash–toria, and maize–rajmash–buckwheat) were tested using a three times replicated split-plot design. The ZT system recorded 13.5 and 3.5% higher system productivity over CT and RT, respectively. Of the four diversified cropping systems, the maize–rajmash–buckwheat system recorded the maximum system productivity (13.99 Mg ha−1) and net returns (3,141 US$ ha−1) followed by the maize–black gram–buckwheat system. Among the tillage practices, ZT recorded the significantly high eco-efficiency index (EEI; 1.55 US$ per kg CO2-eq emission) and the lowest greenhouse gas intensity (GHGI; 0.15 kg CO2-eq per kg production). Of the diversified cropping systems, the maize-rajmash-buckwheat registered the lowest GHGI (0.14 CO2-eq per kg production) and the highest EEI (1.47 US$ per kg CO2-eq emission). Concerning soil nutrient balance, after three cropping cycles, the soil under ZT recorded significantly higher available N (340.0 kg ha−1), P (16.6 kg ha−1), and K (337.3 kg ha−1) over the CT system at 0–10 cm soil depth. Similarly, the soil under the maize–black gram–buckwheat system had the maximum bio-available NPK. Thus, the study suggests that the cultivation of the maize–black gram/rajmash–buckwheat systems under ZT and/or RT would increase farm productivity, profitability, and soil fertility with minimum GHGI in organic farming under the Eastern Himalayan region of India.

The complimentary integration of different enterprises recycled farm waste efficiently and increased the food production and eco-efficiency considerably besides reducing the greenhouse gasses intensity (GHGI) over the existing production system.

Biochar is increasingly gaining popularity due to its extensive recommendation as a potential solution for addressing the concerns of food security and climate change in agroecosystems, with biochar application for increased carbon sequestration, enhanced soil fertility, improved soil health, and increased crop yield and quality. There have been multiple studies on crop yield utilizing various biochar types and application amounts; however, none have focused on the influence of diverse biochar types at various pyrolysis temperatures with different application amounts and the integration of fertilizer regimes in maize crops. Therefore, a two-year factorial field experiment was designed in a temperate Himalayan region of India (THRI) to evaluate the residual effect of different biochar on maize yield under different pyrolysis temperatures, various application rates and fertilizer regimes. The study included three factors viz., amendment type (factor 1), rate of application (factor 2) and fertilizer regime (factor 3). Amendment type included 7 treatments: No biochar- control (A1), apple biochar @ 400 °C pyrolysis temperature (A2), apple biochar @ 600 °C pyrolysis temperature (A3), apple residue biomass (A4), dal weed biochar @ 400 °C pyrolysis temperature (A5), dal weed biochar @ 600 °C pyrolysis temperatures (A6), and dal weed residue biomass (A7). The rate of application included 3 levels: Low (L- 1 t ha−1), medium (M- 2 t ha−1), and high (H- 3 t ha−1). At the same time, the fertilizer regimes included 2 treatments: No fertilizer (N) and recommended dose of fertilizer (F). The results revealed that among the various amendment type, rate of application and fertilizer regimes, the A3 amendment, H rate of application and F fertilizer regime gave the best maize growth and productivity outcome. Results revealed that among the different pyrolyzed residues used, the A3 amendment had the highest plant height (293.87 cm), most kernels cob−1 (535.75), highest soil plant analysis development (SPAD) value (58.10), greatest cob length (27.36 cm), maximum cob girth (18.18 cm), highest grain cob yield (1.40 Mg ha−1), highest grain yield (4.78 Mg ha−1), higher test weight (305.42 gm), and highest stover yield (2.50 Mg ha−1). The maximum dry weight in maize and the number of cobs plant−1 were recorded with amendments A4 (14.11 Mg ha−1) and A6 (1.77), respectively. The comparatively 2nd year of biochar application than the 1st year, the H level of the rate of application than the L rate and the application and integration of the recommended dose of fertilizer in maize results in significantly higher values of growth and productivity in maize. Overall, these findings suggest that the apple biochar @ 600 °C pyrolysis temperature (A3) at a high application rate with the addition of the recommended dose of fertilizer is the optimal biochar for enhancing the growth and productivity of maize in the THRI.

Food security and soil sustainability are the prime challenges to researchers and policy planners across the globe. The task is much more daunting in the fragile ecosystem of the Eastern Himalayan region of India. Soil disturbance from conventional tillage reduces soil productivity and is not sustainable and environmentally friendly. Conservation tillage is regarded as the best crop production practice in the Indian Himalayas, where soil is very easily erodible. Zero tillage alone encourages the growth of different species of weed flora in fragile hill ecosystems. However, live mulching of a pulse crop under zero tillage may be a very beneficial practice, as it aids several soil quality benefits and promotes root proliferation with good crop harvest. Hence, a field investigation was carried out for 3 consecutive years to assess the impact of live mulch-based conservation tillage on soil properties and productivity of summer maize. Five tillage practices, viz. no-till (NT), NT and cowpea coculture live mulch (CLM), minimum tillage (MT), MT+CLM, and conventional tillage (CT), were assessed in a randomized complete block design with three replications. Results revealed that continuous adoption of MT+CLM had the lowest bulk density (1.31 and 1.37 Mg m−3) and maximum water holding capacity (48.49% and 43.1%) and moisture content (22.4% and 25%) at 0–10 and 10–20 cm soil layers, respectively, after 3 years. The infiltration rate (2.35 mm min−1) was also maximum under MT+CLM, followed by NT+CLM. MT+LMC had 13.8 and 27.15% higher available nitrogen and phosphorus, respectively, than CT at 0–10 cm soil depth. The MT+CLM gave a significantly higher maize grain yield (2.63 Mg ha−1), followed by NT+CLM (2.63 Mg ha−1) over the others. A cowpea green pod yield of 1.65 Mg ha−1 was also obtained from the legume coculture. Thus, the study found that live mulch of cowpea under MT/NT improved soil quality and subsequently led to greater productivity of summer maize in the Himalayan region of India.

A study was conducted in nine different topographical locations of Kashmir valley to know the perception of the farmers about climate change. Adaptation and mitigation strategies adopted by the farmers were also documented over a specified period viz., 1980-2019. Results from the observed data revealed warming trends in all seasons, however, winter and spring season temperatures have shown statistically significant increasing trends at the rate of 0.040C/year. Analysis of seasonal and annual precipitation data shows a decreasing trend at the rate of -4.5 mm/ year. The farmers in the study areas had perceived that the climate has changed for the last four decades. Increasing temperature, frequent droughts and less snowfall were the main visual parameters experienced by the farmers. About 30-35% of the farmers have adopted different strategies by default to mitigate ill effects of climate change. However, the majority of the farmers (70%) have not adopted any strategy to cope up with the impacts of climate change. Farmers (>90%) have stressed on provision for an early warning system, timely supply of inputs, provision of financial support and nutrients for soil enrichment as viable options to combat the ill effects of climate change.