Tuti Mangal Deep, Rapolu Mahender Kumar, Sreedevi Banugu, Bandumula Nirmala, Kuchi Surekha, Bandeppa Sonth, Saha Soumya, Parmar Brajendra, Rathod Santosha, Ondrasek Gabrijel, Sundaram Raman Meenakshi
ICAR-Indian Institute of Rice Research, Hyderabad 500030, India.
ICAR-National Rice Research Institute, Cuttack 753006, India.
Plants (Basel). 2022 May 1;11(9):1229. doi: 10.3390/plants11091229.
Integrated management of rice-maize systems is an emerging challenge in southern India due to improper rice residues and tillage management in maize crops. Conservation agriculture (CA) practices such as a reduced tillage and maintaining stubble mulch may hold the potential to increase yields, reduce crop establishment costs and increase farm incomes. A five-year trial was performed to study the effect of different CA and establishment methods in rice on system productivity, profitability, and soil carbon status in a rice-maize system. In the rainy season, the trial consisted of two main treatments: (i) normal manual transplanting and (ii) direct-wet seeding, and three sub-main treatments at different sowing dates with fifteen day intervals. In addition, in the winter season, two tillage treatments (conventional and minimum tillage) were imposed over the rainy season treatments. Both rice and maize were grown under irrigated conditions. The results showed that sowing times at 15 day intervals did not impact the yield significantly. Transplanted rice obtained a significantly higher grain yield during the first four years, but in the last year, the yield was similar in both of the establishment methods. In the winter season, conventional tilled maize recorded a higher cob yield than under the minimum tilled treatment, except for the last year, where both the tillage treatment effects were the same. System productivity of CA-based minimum tilled rice-maize was inferior during the first three years but was superior to the conventionally tilled method in the fourth and fifth year. Pooled analysis revealed that the conventionally tilled rice-maize system resulted in a similar system productivity as that of the CA during the study period. The cost-benefit analysis revealed that transplanted rice and conventionally tilled maize fetched higher net returns of INR 111,074 and INR 101,658/ha, respectively, over the direct-wet seeded rice and CA. In addition, the 15 July rice sown followed by the maize system led to an increase in irrigation water productivity by 15.7%, and the total water (irrigation + rainfall) productivity by 27.1% in the maize crop compared with the 30 July sown system. The CA-based rice-maize system resulted in a significantly higher very labile (0.194%) and labile (0.196%) carbon concentration at a 0-5 cm depth of soil compared to those under the conventional system. Thus, CA can be recommended for southern India and similar agro-ecological tropic and sub-tropic conditions. This system can be followed with appropriate location-specific modification in South-Asian countries, where crop yields and soil health are declining as a result of continuous cereal-cereal crop rotation.
由于玉米作物中水稻残茬和耕作管理不当，水稻-玉米系统的综合管理已成为印度南部面临的一个新挑战。保护性农业（CA）措施，如减少耕作和保留秸秆覆盖物，可能具有提高产量、降低作物种植成本和增加农场收入的潜力。进行了一项为期五年的试验，以研究水稻中不同的保护性农业和种植方法对水稻-玉米系统的生产力、盈利能力和土壤碳状况的影响。在雨季，试验包括两个主要处理：（i）常规人工移栽和（ii）直接湿播，以及在不同播种日期间隔15天的三个次主要处理。此外，在冬季，对雨季处理施加了两种耕作处理（传统耕作和最小耕作）。水稻和玉米均在灌溉条件下种植。结果表明，每隔15天的播种时间对产量没有显著影响。在前四年中，移栽水稻的籽粒产量显著更高，但在最后一年，两种种植方法的产量相似。在冬季，除了最后一年两种耕作处理效果相同外，传统耕作的玉米穗产量高于最小耕作处理。基于保护性农业的最小耕作水稻-玉米系统生产力在头三年较低，但在第四年和第五年优于传统耕作方法。汇总分析表明，在研究期间，传统耕作的水稻-玉米系统的系统生产力与保护性农业的相似。成本效益分析表明，与直接湿播水稻和保护性农业相比，移栽水稻和传统耕作的玉米分别获得了更高的净收益，分别为111,074印度卢比/公顷和101,658印度卢比/公顷。此外，与7月30日播种的系统相比，7月15日播种水稻后接玉米系统使玉米作物的灌溉水生产力提高了15.7%，总水（灌溉+降雨）生产力提高了27.1%。与传统系统相比，基于保护性农业的水稻-玉米系统在土壤0-5厘米深度处的非常不稳定（0.194%）和不稳定（0.196%）碳浓度显著更高。因此，对于印度南部以及类似的农业生态热带和亚热带条件，推荐采用保护性农业。在南亚国家，由于连续的谷物-谷物作物轮作导致作物产量和土壤健康下降，可以对该系统进行适当的因地制宜的修改后采用。
