In the present study,12 new thermo-sensitive,late planted rice varieties have been tested in regional trials in South Guangxi.Variety Boyou 253 was used as control.Out of 12 varieties,three rice varieties,viz.,Yuanfengyou 401,Baiyou 119 and Xiyou 2 showed middle yield and better grain quality.These varieties have shown earlier maturity and could be planted as late rice in South Guangxi,so they could be recommended for the certification by Guangxi Committee for Crop Variety Registration.Six rice varieties,viz.,18A / Gui 99,Lanyou 1972,Boyou 5389,Baofeng 007,Baiyou 838 and Longyou 131 continued for regional trial and production test in 2008,and three varieties,viz.,Boyou 359,Boyou 983 and Yueguiyou 99 were terminated in the test in 2008 due to lower yield,worse grain quality and susceptibility to various diseases,etc.

Third virus-free Daxiyang 1 was used as seed potato for the experiment to compare the effects of different no-tillage cultivation models on yield and economic benefit of potato.The results showed that in five cultivation models,the effects of ditch soil on bottom and covering 6750kg/hm2 rice straw on plant rows were the best,the yield of potato reached 22245.6kg/hm2.Compared to the conventional cultivation method,the yield increased 6547.2kg/hm2 with 41.7%,and the increasing income was 3306.7yuan RMB/hm2.Therefore,this cultivation model could be extended for winter-planting potato production.

试验结果表明:①磷在水稻土中具有显著的后茬效果与缓冲性,一次足量施用,后效可延续至第3季.②多季不施磷,水稻产量并未急剧下降.③连续大量施磷,有减产趋势.