Search

Intensive tillage practices along with improper residue management in a rice (Oryza sativa)–rice system (RRS) contributed to soil fatigue and declining productivity in South Asia. Therefore, a 3-year (2013–2015) field study was conducted to assess tillage modification effects on productivity and soil C sequestration under RRS at ICAR- RC for North Eastern Hill Region, Tripura, India. The experimental site represented two different ecologies: unsubmerged (ECO 1) and submerged (ECO 2), with three tillage practices: conventional tillage (CT), reduced tillage (RT) and no-till (NT). Results showed that the cultivation of RRS under RT produced significantly higher grain (8.6–9.4 Mg ha−1) and straw (11.8–12.9 Mg ha−1) yields under both ecologies over those under CT and RT, in addition to recycling the maximum biomass. Soil under RT had lower bulk density (ρb), the highest soil organic carbon (SOC) concentration, pool, sequestration, accumulation, carbon retention efficiency, soil microbial biomass carbon and dehydrogenase activities under both ecologies as compared to CT. A total amount of 1.34 Mg C ha−1 was accumulated under soils of RT over 3 years. The rate of SOC sequestration ranged from 133.6 kg ha−1 year−1 under soils of CT to 444.7 kg ha−1 year−1 under RT in RRS. Thus, cultivation of RRS under RT with effective residue recycling is recommended for higher system productivity and C sequestration under both rice production ecologies of the NEH region of India. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effects of tillage and mulch on weed growth, soil moisture storage, productivity and profitability of upland rice during 2012-2013 at Lembucherra, India. Tillage treatments included CT-RI: conventional tillage with 100% residue incorporation and NT-RR: no-till with 100% residue retention. Mulches included rice straw (SM), Gliricidia (GM), brown manuring (BM) and none (NM). CT-RI registered the highest total weed density (89-168 weeds m−2) and biomass (9.6-183 g dry weight m−2) than those for the NT-RR (75-161 weed m−2 and 8-155 g dry weight m−2). In addition, NT-RR stored (122-172 mm) more soil moisture (0-40 cm soil depth) in comparison with that for the CT-RI treatment (110-161 mm) during crop growing season. Tillage treatments did not have the significant effect on yields. NT-RR reduced the cost of cultivation by 31.5% compared with that for the CT-RI. Thus, the net returns under NT-RR were more than those for the CT-RI. The BM recorded the lowest weed biomass and density as compared to that under other mulches. Therefore, cultivation of upland rice using NT along with BM mulching enhanced productivity and profitability of rice cultivation in India. [ABSTRACT FROM AUTHOR]