Runoff and soil erosion in the integrated farming systems based on micro-watersheds under projected climate change scenarios and adaptation strategies in the eastern Himalayan mountain ecosystem (India)

Land degradation caused by soil erosion (SE) in forests converted into cropland under climate change, particularly with increased rainfall intensity, is of great concern to the agricultural sustainability of the tropical mountain ecosystem. We evaluated the response of six hilly micro-watersheds (HMW) under different Integrated Farming Systems (IFSs) to SE in multi-model climate change scenarios using the Water Erosion Prediction Project (WEPP) model. The IFSs were forestry (HMW₁), abandoned shifting cultivation (HMW₂), livestock with fodder crops (HMW₃), agroforestry (HMW₄), agri-horti-silvi-pastoral (HMW₅), and horticulture (HMW₆) established on a hilly slope (32.0-53.2%) of the eastern Himalayas (Meghalaya, India). The WEPP model was calibrated and validated with measured runoff and soil loss data of 24 years for each of the six IFSs. The projected annual SE (average) for all HMWs increased in all RCPs. The IFS based on shifting cultivation (HMW₂) was the most vulnerable, with the highest percentage increase in SE (46-235%) compared to the baseline years (1976-2005) under RCP 8.5. The cultivated IFSs (HMW₃ to HMW₆) had 47.8-57.0% less runoff and 39.2-74.6% less soil loss than HMW₂ under RCP 8.5. Of these, HMW₆ followed by HMW₄ and HMW₅ were the most effective at minimizing soil loss. Simulation results showed a reduction in soil loss through adaptive strategies such as mulching with broom grasses, stones, field beans, and the introduction of subsurface drainage. Adoption of IFS based on horticulture and agroforestry with bio-mulching on steep slopes is an effective measure to control soil erosion in the eastern Himalaya (India).

Diversification Options in Sugarcane-Based Cropping Systems for Doubling Farmers' Income in Subtropical India

Crop diversification provides an opportunity for farmers to maximize their profits, fulfilling multiple needs, avoid monsoon threats, and make the crop production system sustainable. Inclusion of various pulse/oilseed/vegetables/cereals/medicinal/aromatic crops with sugarcane brings forth cultivation of these crops in irrigated agro-system and improves the yields of component crops. Besides, the component crops improve soil fertility and create a favorable environment for the further growth of sugarcane crops. Sprouting in winter-initiated sugarcane ratoon could be enhanced by adopting fodder legumes such as Indian clover and Egyptian clover. Intercropping vegetables provides an ample opportunity for mid-season income generation and improves profitability. Besides, high-value medicinal and aromatic crops such as tulsi (holy basil), mentha could also be included in the sugarcane-based system. Crop residue management has been recognized as a critical issue in managing the crops in the various cropping systems. Including multiple bio-agents for fast decomposition of crop residues provides scope for managing soil organic carbon through crop residue recycling in the system. Resource use efficiencies, nutrient use, water use, and weed control could be increased by adopting suitable crops in intercropping systems. An integrated farming system involving crop, livestock, and fisheries options could improve farmers' profit besides employment generation in rural India. Recycling of bye products and co-products of other enterprises influences the viability and farmer's profitability of the system. Trash, press mud cake, vinasse, composted bagasse, rhizodeposition of stubble play a significant role in sustaining soil fertility and increasing crop productivity. New emerging crop diversification options, viz., intercropping of rajmash, winter maize, and garlic in autumn cane generate mid-season income and enhance the system's profitability for small and marginal cane growers. Dual-purpose legumes, viz., cowpea, and green gram as intercrops with spring-planted cane increase the pool of soil microbial biomass nitrogen capitalize allelopathic effects and sustain soil health. In the present paper, these issues have been discussed. Due to the adoption of location-specific and farmers-centric systems, farmers' profitability could be increased, providing sustainability to the sugarcane-based systems.

Comparing rice production systems in China: Economic output and carbon footprint

In recent years, many rotational and integrated rice production systems coupled with several greenhouse gas (GHG) emissions mitigation practices have been developed and adopted for demand of low carbon production. However, there have been only few studies about comparisons on the balance between high production and mitigation of GHG emissions in different rice production systems. We therefore aimed to evaluate economic output and carbon footprint of different rice production systems, based on several long-term experiments conducted by our lab. CH₄ and N₂O emission were measured by the same static chamber/gas chromatogram measurement procedure in different rice production systems, including rice-fallow, rice-rapeseed, rice-wheat, double rice, and integrated rice-crayfish production system. Then, we applied the DeNitrification DeComposition model to simulate CH₄ and N₂O emission over different years under the same condition for comparison. Carbon footprint was calculated following the process-based life cycle assessment (PLCA) methodology. The economic benefit of rice production systems was assessed by cost-benefit analysis. According to the analysis, the double-rice production system exhibited the highest intensity of carbon footprint (ICF = 4.14 kg CO₂-eq yuan^-1), rain-fed treatment in the rice-rapeseed system had the lowest (ICF = 0.68 kg CO₂-eq yuan^-1). The intensity of carbon footprint in different treatments in the integrated rice-crayfish production system was around 0.8 kg CO₂-eq yuan^-1. Overall, the results of this case study suggest: (1) the proposed practices in different rice production systems are no straw returning (rice-fallow), no-tillage without straw returning (rice-wheat), rain-fed farming (rice-rapeseed), no insect and no inoculation (double rice), and feeding with straw returning (rice-crayfish); (2) rotational and integrated systems can achieve high net output with low carbon emission; (3) reducing the amount of nitrogenous fertilizer application is the most important and effective GHG mitigation practice for rotational systems.

Integrated farming system producing zero emissions and sustainable livelihood for small-scale cattle farms: Case study in the Mekong Delta, Vietnam

This study proposes an integrated cattle breeding and cultivation system that provides zero emission and sustainable livelihood for the community in rural areas. The proposed integrated farming system improves agricultural productivity and environmental and sanitation conditions, minimizes the amount of waste, and increases the family income up to 41.55%. Several waste types can be recycled and transformed into valuable products, such as energy for cooking, organic fertilizer for crops, and cattle feed for breeding. Wastewater effluent from the biogas tank can be treated by biochar and results show that it then meets the standards for irrigation purposes. Also, the waste flow from cattle breeding supplies enough nutrients to cultivate plants, and the plants grown supply are adequate food for the 30 cows living on the farm. This research shows that the use of an integrated farming system could achieve zero-emission goal. Thereby, it provides a sustainable livelihood for cattle breeding family farms. The proposed integrated cattle breeding and cultivation system improves agricultural productivity, environmental and increases the farmer income up to 41.55%.