Permanent beds for rice-wheat systems in Punjab, India. 1: Crop performance

摘要

The performance of rice and wheat grown in rotation on permanent beds over 3-4 years in small plots, replicated experiments and large (60 m long) blocks was evaluated on sandy loam and loam soils in Punjab, India. Yield of wheat on fresh and permanent beds in both small plots and large blocks was usually similar to yield of conventionally tilled wheat (CTW) on the loam, but tended to be lower on the sandy loam. There was no evidence of a decline in wheat yield on the beds relative to CTW as the beds aged. Yield of both transplanted and direct-seeded rice on beds on both soils declined significantly relative to puddled transplanted rice (PTR) as the beds aged, in contrast to findings in the eastern Indo-Gangetic Plain (IGP) where yields of transplanted rice on permanent beds were higher than in PTR. The different performance of permanent beds in the eastern and western IGP needs further examination to understand the reasons and to develop successful permanent bed systems for the western IGP. The results of our work suggest that, with current technology, permanent bed RW systems in Punjab, India, are not viable if rice yield is to be maintained at the levels achieved with PTR.