Conservation agriculture options for a Rice-Maize cropping systems in Bangladesh

Abstract

Over the last two decades, Rice (Oryza sativa L.)-Maize (Zea mays L.) cropping systems have become one of the most dominant cropping systems in Bangladesh. This has coincided with the expansion in use of two-wheel tractors, which has facilitated options for minimum tillage. A three-year trial examined the prospects of conservation agriculture practices for Rice-Maize cropping in Bangladesh, with respect to minimum tillage and residue retention. Main plot tillage treatments of conventional full tillage, single pass wet tillage in rice (rotated with zero tillage in maize), bed planting and strip tillage were combined with residue retention treatments of 0, 50 and 100% in sub-plots. Compared to conventional tillage, minimum tillage saved 60-66% of fuel and 70-74% of labour required for land preparation. Although minimum tillage reduced the land preparation cost significantly through saving fuel and labour, weed infestation was higher compared to conventional tillage, which influenced the cost of production. Rice seedlings transplanted under unpuddled strip tillage required more time than in conventional or single pass wet tillage due to poor visibility of strips and the hard surface of untilled soil. Bed planting incurred the lowest production cost. Tillage methods and residue treatment produced no significant grain yield differences. Rice grown with single pass wet tillage and maize grown with strip tillage gave the highest gross margin over time. Despite lack of treatment effects on yields, the results suggest that profitability of Rice-Maize cropping could be increased with minimum tillage, provided there is adequate control of weeds by herbicides.

Conservation Agriculture for Rice-Based Intensive Cropping by Smallholders in the Eastern Gangetic Plain

“…Research and development in Bangladesh have developed effective CA practices for smallholder farms in the EGP using minimum soil disturbing implements mounted on 2WTs. The key outcomes are new knowledge developed on: (i) effective strip planting using the VMP [4][5][6]; (ii) planting machinery development and performance testing in the small fields using 2WTs [4,9]; (iii) agronomy for mechanised seeding with minimum soil disturbance and residue retention [5,6]; (iv) weed dynamics and weed management under CA [11][12][13][14][15][16]33]; (v) crop rotation effects on soils and weeds [33,34]; (vi) mechanised transplanting of NPT rice [24,25]; (vii) soil improvement under CA [17][18][19][20][21][22]; (viii) decreased greenhouse gas emissions under CA [23]; (ix) increased profit from CA-based SP + NPT rice in farmers' fields [8]; (x) water balance [27], which showed that wheat under CA (SP and increased residue retained) required 11-33% less irrigation water than the convention practices; and (xi) commercialisation models for sales of planters to LSP [31]. Based on the evidence presented, there should now be sufficient confidence for more widespread demonstrations across different agro-ecosystems in the EIP and for programmes to engage the private sector and farmers in adoption and out-scaling of CA for smallholder rice-based crop production in the EGP.…”

“…After 2.5 years in both legume-and cereal-dominated rotations, the soil organic carbon (SOC) concentration and SOC content at 0 to 7.5 cm soil depth were greater in SP + NPT than CT + CP [17]. By contrast, the SOC concentration and content at 7.5 to 15 cm remained unchanged between CT + CP and SP + NPT.…”

Rice (Oryza sativa L.) Establishment Techniques and Their Implications for Soil Properties, Global Warming Potential Mitigation and Crop Yields

“…Even more N is released when tillage coincides with periods of high soil temperature and/or moderate soil moisture [23,43]. The excess mineralized N after fulfilling the low demand of N by crops at the initial stage of crop might end up in loss via denitrification, nitrate leaching, ammonia volatilization or surface runoff [44,45].…”

“…Chakraborty et al [6] reviewed global data of soil properties, C and N cycling and greenhouse gas implications under emerging and conventional practices of crop production. However, the alterations in C and N cycling and GHG emissions from soils under conventional and promising CA practices have not been quantified in the intensively cropped Eastern Gangetic Plains (EGP) [6,23]. The literature also lacks C footprint data of the rice-based cropping systems when CA practices sequester C from the atmosphere into long-lived SOM pools in the subtropical humid region [24].…”

Effect of Conservation Tillage on Soil Chemical Properties in Rice-Maize Cropping System

“…Maize is grown in dry conditions whereas rice is grown in wet land conditions. Rice grown in minimum tillage under unpuddled transplanting conditions decreased the production cost and increased the profitability (Islam et al, 2014). Unpuddled transplanting is gaining attention to the rice growing farmers in Bangladesh.…”