干旱区生态环境知识资源中心

One of the resource conservation technologies for rice (Oryza sativa) is direct seeding technique, which may be more water efficient and labour cost-effective apart from being conducive for mechanization. The crop establishment during the initial stages may depend upon the method of direct seeding, cultivar and seed rate. A study was carried out during 2004-2005 to evaluate the effect of different seeding techniques, cultivars and seed rates on the performance of direct-seeded basmati rice in loamy sand (coarse loamy, calcareous, mixed hyperthermic, Typic Ustipsamments) at Punjab Agricultural University, Ludhiana, India. The treatments in main plots included four seeding techniques (broadcast in puddled plots, direct drilling in puddled plots, direct drilling in compacted plots and direct drilling under unpuddled and uncompacted conditions). The subplots treatments comprised of two cultivars (Pusa Basmati-1 and Basmati-386) and three seed rates (at 30, 40 and 50 kg ha(-1)).

The moisture retention and bulk density at harvest were sufficiently lower in uncompacted/unpuddled plots than compacted or puddled plots more so in 0-30 cm soil layer. The crop stand establishment was higher in direct-drilled compacted plots with 50 kg seed ha-1. It was higher in Pusa Basmati-1 than Basmati-386. The direct drilling after compaction produced 28% higher biomass than uncompacted/unpuddled plots. Similar trend was observed in leaf area index and effective tillers. Effective tillers were significantly higher with 30 kg seed ha-land were higher in Pusa Basmati-1 than Basmati-386. The root mass density of basmati rice in 0-15 cm soil layer at 45 days after sowing was 1549 g m(-3) in compacted soils, 1258 g m(-3) in broadcasting in puddled soil and 994 g m-3 with direct drilling in puddled soil. The grain yield of basmati rice was 44% and 30% higher in direct-drilled compacted and puddled plots, respectively, than uncompacted/unpuddled plots. (C) 2007 Elsevier B.V. All rights reserved.