Energy and carbon budgeting of traditional land use change with groundnut based cropping system for environmental quality, resilient soil health and farmers income in eastern Indian Himalayas

Trends in phytoremediation of heavy metals-contaminated soils: A Web of science and CiteSpace bibliometric analysis

Heavy metals pollution in soils is an urgent environmental issue worldwide. Phytoremediation is a green and eco-friendly way of remediating heavy metals. However, a systematic overview of this field is limited, and little is known about future development trends. Therefore, we used CiteSpace software to conduct bibliometric and visual analyses of published literature in the field of phytoremediation of heavy metals in soils from the Web of Science core collection and identified research hotspots and development trends in this field. Researchers are paying increased attention to phytoremediation of heavy metals in soils, especially environmental researchers. A total of 121 countries or regions, 3790 institutions, 4091 funded organisations and 15,482 authors have participated in research in this area. China, India, and Pakistan are the largest contributors. There has been extensive cooperation between countries, institutions, and authors worldwide, but there is a lack of cooperation among top authors. 'Calcareous soil', 'Co-contaminated soil' and 'Metal availability' are the most intensively investigated topics. 'EDTA', 'Plant growth-promoting Rhizobacteria', 'Photosynthesis', 'Biochar' and 'Phytoextraction' are research hotspots in this field. In addition, more and more researchers are beginning to pay attention to research on co-contaminated soil, metal availability, chelating agents, and microbial-assisted phytoremediation. In summary, bibliometric, and visual analyses in the field of phytoremediation of heavy metals in soils identifies probable directions for future research and provides a resource through which to better understand this rapidly advancing subject.

Evaluation of millets for physio-chemical and root morphological traits suitable for resilient farming and nutritional security in Eastern Himalayas

Introduction

Millets are nutritionally superior and climate-resilient short-duration crops and hold a prominent place in cropping sequences around the world. They have immense potential to grow in a marginal environment due to diverse adaptive mechanisms.

Methods

An experiment was conducted in an organic production system in the North Eastern Himalayan foothills of India for 3 consecutive years by evaluating high-yielding varieties (HYVs) of different millets, viz., finger millet, foxtail millet, little millet, barnyard millet, proso millet, and browntop millet, along with local landraces of finger millets (Sikkim-1 and Sikkim-2; Nagaland-1 and Nagaland-2) to identify stable, high-yielding, and nutritionally superior genotypes suited for the region.

Results

Among the various millets, finger millet, followed by little millet and foxtail millet, proved their superiority in terms of productivity (ranging between 1.16 and 1.43 Mg ha^-1) compared to other millets. Among different varieties of finger millets, cv. VL Mandua 352 recorded the highest average grain yield (1.43 Mg ha^-1) followed by local landraces, Nagaland-2 (1.31 Mg ha^-1) and Sikkim-1 (1.25 Mg ha^-1). Root traits such as total root length, root volume, average diameter of roots, and root surface area were significantly higher in finger millet landraces Nagaland-1, Nagaland-2, and Sikkim-1 compared to the rest of the millet genotypes. The different millets were found to be rich sources of protein as recorded in foxtail millet cv. SiA 3088 (12.3%), proso millet cv. TNAU 145 (11.5%), and finger millet landraces, Sikkim-1 and Nagaland-2 (8.7% each). Finger millet landrace Sikkim-2 recorded the highest omega-6 content (1.16%), followed by barnyard millet cv. VL 207 (1.09%). Barnyard millet cv. VL 207 recorded the highest polyunsaturated fatty acid (PUFA) content (1.23%), followed by foxtail millet cv. SiA 3088 (1.09%). The local finger millet landraces Sikkim-1 and Sikkim-2 recorded the highest levels of histidine (0.41%) and tryptophan (0.12%), respectively. Sikkim-1 and Nagaland-2 recorded the highest level of thiamine (0.32%) compared to the HYVs.

Conclusion

These findings indicate that finger millet has great potential in the organic production system of the North Eastern Himalayan Region (NEHR) of India, and apart from HYVs like VL Mandua 352, local landraces, viz., Nagaland-2 and Sikkim-1, should also be promoted for ensuring food and nutritional security in this fragile ecosystem.

Integrating conservation agriculture with intensive crop diversification in the maize-based organic system: Impact on sustaining food and nutritional security

Introduction

Developing an intensive sustainable model and feeding a rising population are worldwide challenges. The task is much more daunting in the North Eastern Himalayas, where, low productive maize (Zea mays)maize (Zea mays) fallow is the main production system in the upland. To increase farm productivity, nutritional security, and energy dietary returns while maintaining environmental sustainability and economic viability, short-duration crops must be included in the maize–fallow system.

Methods

A field study was conducted in sandy clay loam soil with a randomized complete block design with three replications for three continuous years (2018–2021) under organic management with two crop management practices, viz., (i) conservation agriculture and (ii) conventional agriculture, and six crop diversification options, viz., (i) maize–sweet corn (Zea mays saccharata)–vegetable pea (Pisum sativa) (M-SC-VP), (ii) maize–sweet corn-mustard (Brassica juncea) (M-SC-M), (iii) maize–sweet corn–lentil (Lens culinaris) (M-SC-L), (iv) maize–sweet corn–vegetable broad bean (Vicia faba) (M-SC-VB), (v) maize (local)–vegetable pea (M-VP), and (vi) maize (local)–fallow (M-F).

Results

The results showed that, the average system productivity was 5.3% lower for conventional agriculture than conservation agriculture. System carbohydrate, protein, fat, dietary fiber, and dietary energy were ~6.9, 6.8, 7.8, 6.7, and 7%, higher in conservation agriculture than in conventional agriculture, respectively. Similarly, system macronutrients (Ca, Mg, P, and K) and system micronutrients yield (Fe, Mn, Zn, and Cu) were, 5.2–8% and 6.9–7.4% higher in conservation agriculture than in conventional agriculture, respectively. On average, over the years, crop diversification with M-SC-VP/M-SC-VB intensive crop rotation had higher system productivity (158%), production efficiency (157%), net returns (benefit–cost ratio) (44%), and dietary net energy returns (16.6%) than the local maize–vegetable pea system. Similarly, the M-SC-VP/M-SC-VB system improved the nutritional security by improving Ca, Mg, P, K, Fe, Mn, Zn, and Cu yield by 35.5–135.7% than the local M-VP system.

Discussion

Conservation agriculture with M-SC-VP/M-SC-VB rotation showed significantly (p < 0.05) higher productivity, carbohydrate yield, protein yield, fat yield, and dietary fiber production. It is concluded that conservation agriculture improved soil health and performed better than conventional agriculture in maize-based intensive cropping systems. Overall results indicate that crop diversification with M-SC-VP/M-SC-VB can potentially increase calorie and protein consumption and farm profitability.

Redesigning of Farming Systems Using a Multi-Criterion Assessment Tool for Sustainable Intensification and Nutritional Security in Northwestern India

Sustaining agricultural systems dominated by small and vulnerable resource-poor farms that are subject to climatic aberrations is a major challenge for most Asian countries. In this context, the role of agriculture requires immediate attention in northwestern India where marginal farmers with less than a meagre 1 hectare of land represent about 67% of the population. Research based on prototype farms is being promoted in the redesign of current farming practices to help give these farmers sustainable livelihoods. We hypothesize that integrating innovative cropping systems into smallholder marginal farms could help to achieve these objectives. The study presented here describes a modelling approach for the ex-ante assessment of the current farming practices of marginal households in terms of economic, environmental, and nutritional indicators in comparison with those of experimental research farms in order to delineate an alternative scope of flexibility to optimize farming practices. We used the FarmDESIGN model to evaluate farmers’ realities, with a focus on marginal farms (marginal poor farmers (MPFs)) and marginal diversified farmers (MDF) with the objective of enhancing profit, soil organic matter balance, and nutritional system yield in terms of dietary energy and reducing pesticide usage. Introducing prototype cropping systems in up to 33% of the farm area, combined with rearrangements of the existing crops, provided ample opportunity to improve farm performance. The improvements were greater when prototype cropping systems were added, and MPFs could benefit greatly from improvements in soil organic matter balance when considering the current negative organic matter balance of most farms. We conclude that the model-based approach of evaluating the potential of new cropping systems, along with the fine tuning of alternative combinations, will support the enhanced adaptability of innovative cropping practices, which will help to improve the livelihoods of marginal farmers.

The Policy Effect, Spatial Heterogeneity, and Spillover Effect of Land System Pilots

As an important way to innovate the pattern of land reform, the land system pilots serve as the crucial driving force in promoting rural economic development under the background of rural revitalization. Based on the panel data of 10 pilots along the Yellow River basin, this paper chose 111 near and distant neighboring regions from 2009 to 2018. This paper tested the spillover effects and regional heterogeneity characteristics of the land system pilots using the propensity score matching-difference-in-differences (PSM-DID) method and regression discontinuity design (RDD). The results are as follows: first, the land system pilots have a significant and general impact on regional economic development; second, the establishment of the land system pilots has different impacts on the economic development of near and distant neighboring regions, which shows obvious policy-effect spillovers; and third, the land system pilots have the strongest stimulating effect on the economic development of the middle reaches of the Yellow River basin, as well as the weakest stimulating effect on upstream regional economic development, which shows the significant spatial heterogeneity of policy effects. The results of the research study are of great significance for the exploration of regionally differentiated system-supply pilots under the background of rural revitalization. Additionally, this study has important implications for further land system improvements and rural economic developments.