东莞桥头镇农业生态系统模式的研究

为探索东莞市桥头镇的农业现代化，运用面上调查和定点分析的研究方法，概括了全镇现有的４大类农业生态系统模式，对其进行了能流和磷流分析，得到如下结果：规模经营的综合种养场水稻产出较高，纯收益较好，光能利用和辅助能能效较高，而传统小规模水稻则有机肥投入比例大，磷效高；单－蔬菜种植模式的菜场，干物产量低，光能利用率和辅能能效低，磷素投入高，但有机磷比例低，故磷效低，但经济效益好。综合种养场猪和鱼的养殖，生产成本低，经济效益好，养猪和鱼分别可将生活废弃物中３９．６２％和１２．６８％的磷转化为产品磷。农科园集约化鸡场能量产投比低，但对全价饲料中磷素的转化率高达６２．６５％。本文还就该镇在新的经济环境下，调整农业布局、采纳王高农业模式方面展开了论述。

Agroeccovstem Models at Qiaotou Town Dongguan City,Guangdong Province

Through 8eneral survey and case studies,four tThical asroecoSystem medels inOaotouTown were seiected to study their energy flow and phosphorus cycling. These models are trad-itiopnl small scale rice farm(SRF),commercial vegetable farm(CVF),commercial chicken farm(CcF)and integrated model farm(IMF)which liave rice,pig,fish and poultry productions. Themain rcauIts are as follows:in IMF rice field,theproductivity,effeciency of solar radiation andfossil fuel are higher than rice in SRF,profits are better,but the ratio of organic-P to total-P andits effeciency of P is lower than that of the rice in SRF;the preductivity of the vegetables in CVFis lowest,its solar radiation and faseil fuel effeciency are also the lowest among CVE,SRF andIMF,but its profits are the best,its input of P is the largest,however,its organic-P input islowest,the output/input ratio of P is the lowest.The piggery and fishpond in IMF get good profitsbecause of their low cost,they can turned 39. 62%and 12.68%Pof the wastes into theirpreducts respectivily;the energy effeciemcy of chicken in CCF is low,62.65%Pof the commer-c1al comple te feed can be turned in to its products.A discussion is also made on the arrangementand extention of the high-yield,high-quality,high-benifi t agroecosystem modeis in Qiaotou.