“黑麦草─水稻”草田轮作系统的研究Ⅲ意大利黑麦草引进品种在南亚热带地区稻底撒播条件下的生产能力

A Study of an Italian Ryegrass(Lolium Multiflorum)-Rice(Oriza Sativa)Rotation(IRR)System Ⅲ Productivity of Introduced Varieties of Italian Ryegrass when seeded into Late rice Population in the Southern Subtropics of China

为了进一步研究“黑麦草一水稻”草田轮作（简称ＩＲＲ）系统的适用种质及其在稻底撒播条件下的生产力，应用８个从日本引进的意大利黑麦草（简称ＩＲＧ）品种以及１个从江西省引进的当地农家品种，在稻底撤播和板田条播条件下进行了栽培试验（总施氮３００ｋｇ／ｈｍ２）。８个引进品种是樱早生（极早熟、浅根系）、早生丰、早生育叶、立早生、妙奇青叶（均为早熟）、普通种（中熟）、双春（晚熟）和艾思（晚熟）。

Eight varieties of Italian Ryegrass(IRG)introduced from Japan and one native variety from Jiangxiprovince of China were cultivated in two cases,one of that the seeds of IRG were broadcasted into growinglate rice population and another seeded in drill under no-tillage condition after rice harvested.Totalnitrogen input was 300kg/ hm2 for both.The introduced varieties were Sakurawase(extremely earlyvariety),Waseyutaka(early),Waseaoba(early),Tachiwase(early),Miyukiaoba(early),Common(middle),Futaharu(late)and Eisu(late).Main resuIts are summarized as follows:1.A high average yield of IRG,6900kg/hm2 in dry matter was gained.aIthough there were a long-term drought weather in sowing and seedling growing period and a contin uous low temperature and rainyweather from Feb.to Apr,It is therefore indicated that the IRG sub-system of IRR system is muchstable even to the changeable climate in the southern subtropics of China 2.It is again proved that the early varieties is more preductive than those late ones,and so it would benecessary to develop the introduced early varieties. 3.Yields of IRG from that seeding was carried out before rice harvest were higher than from drillseeding condition. The fact shows that IRG has adaptability to no-tillage and shady condition. The meritsof seed ing before rice harvest could be attributed to improvement of water condition and prolongation ofgrowth period. 4.According to the plasticity of crude protein content correlating with synthetical properties of soil,thetotal nitrogen input should be more than 300kg/hm2.