Deteriorating soil health, diminishing soil organic carbon (SOC), development of subsurface hard compact layer and declining system productivity are barriers to achieving sustainable production in the traditional rice–wheat cropping system (TA) in the eastern Indo-Gangetic Plain of India. Conservation agriculture (CA), which favours minimum soil disturbance, crop residue retention and crop diversification could be a viable alternative to the TA to address most of those major problems. With that in mind, a long-term experiment is being implemented at ICAR-RCER, Patna, Bihar, India, with four treatments: (a) TA, (b) full CA (fCA) and (c and d) partial CA (pCA1 and pCA2), differing in crop establishment methods, cropping system and crop residue management in a randomized complete block design. Measurement of soil health parameters was carried out in the 11th year of the experiment. The results revealed a beneficial effect of CA and 46 and 40% increase in SOC concentration and stock, respectively, under fCA over TA in the 0–7.5-cm soil layer. The effect of partial CA (pCA1 and pCA2) was variable, but an increasing trend was always observed under pCA compared to TA. There was an enrichment in SOC content of aggregates under CA irrespective of size class; however, no relation was found between SOC content and aggregate diameter. The contribution of macroaggregates to SOC stock was larger (36–66%) under CA in the 0–7.5-cm soil layer. Adoption of CA improved the macroaggregate content, MWD and GMD of aggregates, and aggregation ratio. Soil macropore content was greater under fCA, whereas other parameters were similar among treatments. The impact of CA was mostly limited to 0–7.5 cm soil layer and a maximum up to 15 cm soil depth while evaluation until 60 cm soil depth was realized. The yield of rice in CA was comparable to or higher than in TA, whereas the system rice equivalent yield was always higher (38–53%) under CA than under the conventional practices. Therefore, a CA-based cropping system must be encouraged, to increase SOC status, improve aggregation stability and, consequently, sustain or increase system productivity, in order to achieve food and nutritional security in the eastern Indo-Gangetic Plain of India.

中文翻译：

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印度东部恒河平原的长期保护性农业能否提高产量、土壤碳和聚集性？


土壤健康恶化、土壤有机碳（SOC）减少、地下坚硬致密层的发展和系统生产力下降是印度东部恒河平原传统稻麦种植系统（TA）实现可持续生产的障碍。保护性农业（CA）有利于最小化土壤扰动、作物残茬保留和作物多样化，可能是技术援助的可行替代方案，可以解决大多数主要问题。考虑到这一点，印度比哈尔邦巴特那的 ICAR-RCER 正在实施一项长期实验，有四种治疗方法：(a) TA、(b) 完全 CA (fCA) 和 (c 和 d) 部分 CA ( pCA1 和 pCA2），在随机完整区组设计中的作物种植方法、种植系统和作物残留管理方面有所不同。土壤健康参数的测量在实验的第11年进行。结果表明，在 0-7.5 厘米土层中，fCA 相对 TA 下的 CA 具有有益效果，并且 SOC 浓度和储量分别增加了 46% 和 40%。部分CA（pCA1和pCA2）的影响是可变的，但与TA相比，pCA下总是观察到增加的趋势。无论尺寸等级如何，CA 下骨料的 SOC 含量都会增加；然而，未发现 SOC 含量与聚集体直径之间存在任何关系。 CA 作用下 0-7.5 厘米土层中大团聚体对 SOC 储量的贡献更大（36-66%）。 CA的采用提高了大骨料含量、骨料的MWD和GMD以及聚集率。 fCA 下的土壤大孔含量更高，而其他参数在处理之间相似。 CA 的影响主要限于 0-7。5厘米土层，最大土深15厘米，评价直至60厘米土深。 CA 的水稻产量与 TA 相当或更高，而 CA 下的系统水稻当量产量始终高于常规做法（38-53%）。因此，必须鼓励基于 CA 的耕作制度，以提高 SOC 状态，提高聚集稳定性，从而维持或提高系统生产力，以实现印度东部印度恒河平原的粮食和营养安全。