关键词: 稻-虾模式, 资源利用效率, 经济效益, 播期, 品种

Abstract: The effects of different sowing dates[regular sowing date: June 15 (CK);early sowing date:May 20 (M1);postponed sowing date:July 10 (M2)]and different rice varieties on utilization efficiencies of light,temperature and water under rice-shrimp system were studied,so as to provide a theoretical basis for efficient use of resource of rice-shrimp system.The results showed that the rice yield decreased gradually with the delay of sowing date,which was 7.4—13.0 t/ha,and there were significant differences among the three sowing dates and the different rice varieties; production efficiencies of light energy and temperature decreased with the delay of sowing date;economic benefit increased with the delay of sowing date.Compared with M2 treatment,M1 treatment increased the production efficiencies of light energy and temperature,water use efficiency by 26.7%,18.2% and 18.8%,respectively.The economic benefit of M2 treatment was the highest,which increased by 41.5% and 10.7% compared with M1 treatment and CK,respectively. Yongyou 4949,Shengtaiyou 018 and Zhongjiazao 17 all had higher yields,production efficiencies of temperature and light energy,water use efficiencies and economic benefits than the other rice varieties under the same sowing date.To sum up,M2 treatment with rice varieties of short growth period had the lowest utilization efficiencies of light,temperature and water,but the highest economic benefit,indicating that the rice-shrimp system could appropriately delay the shrimp harvesting time to early July,at the same time,rice varieties with higher yield and more efficient utilization of resources should be selected under the premise of ensuring economic benefit.

Key words: Rice-shrimp system, Resource utilization efficiency, Economic benefit, Sowing date, Variety