^(15)N标记绿肥喂猪后还田的转化和效益的研究

EFFICIENCY AND TRANSFORMATION OF^(15)N-LABELLED GREEN MANURE AFTER FEEDING PIG AND APPLYING TO PADDY FIELD

本文用￣（１５）Ｎ标记绿肥与无Ｎ淀粉配制成饲料喂猪，猪体平均回收饲料￣（１５）Ｎ２３．５１％；猪粪回收￣（１５）２３．８５％，猪尿回收￣（１５）Ｎ２８．７６％；饲料绿肥Ｎ的总回收率为７６．１２知。猪粪、尿还田，水稻全株对Ｎ的回收分别相当于饲料绿肥Ｎ的３．７５％和７．２５％。其中转化至稻谷的分别为２．５１％和４．８２％。以经济产品计算，猪体和稻谷共回收饲料绿肥￣（１５）Ｎ３０．８４％，比￣（１５）Ｎ绿肥与尿素配施还田稻谷回收的绿肥Ｎ（为２６．６５％）相对地高１５．７％。

15)N-labelled green manure mixed with nitrogen-free starch was used to feed pigsin the study.The results showed that the amount of ￣(15)N transformed into the bodiesof the two slaughtered pigs accounted for 23.51% on average,of the total amountof￣ (15)N deposition in the experimental diet taken by each pig.The￣(15)N excreted thr-ough the feces and urine of the two pigs accounted for 23.85% and 28.76% ,respe-ctively,of the total amount of ￣(15)N deposition in the feed(green manure)of pigs,The average recovery of total ￣(15)N for the two pigs was 76.12%. At the same time,the mean digestibilities of carbohydrates for two pigs was 75.63%。The results ofrice micro-plot experiment showed that the amount of ￣(15)N transformed from pig fecesand urine into whole rice plant accounted for 3.75% and 7.25% of the total amountof ￣(15)N deposition of the feedgreen manure respectively,of which 2.5 1% and 4.82%of the total ￣(15)N were transformed into rice grain,respectively.The pig bodies andrice grain recovered altogether 30.84% of the feed-green manure N,being 15.7%relativly higher than that in the plot of combined application of green manure andurea where rice grain recovered 26.65% of the ￣(15)N -labelled green manure N.