有機稻田雜草害防治

Abstract

本研究自2001年二期作至2002年二期作連續三期作進行田間試驗，探討有機稻田不同雜草控制方法的防治效果，及其對水稻生長、產量和稻米品質之影響。連續三期作試驗結果顯示，2002年一期作以紙膜及飼鴨處理抑制雜草效果最佳，抑制效果均達99%以上；滿江紅及米糠抑制雜草效果次之。2002年二期作試驗結果顯示，仍以紙膜敷蓋處理對雜草的防治效果最好，而飼鴨處理抑制雜草效果亦佳，抑制效果達99.5%，黃豆粉施用0.3kg/ m2即可有效抑制雜草族群 74.8%。施用米糠也造成相同結果， 0.5kg/m2用量即可。 2001二期作、 2002一、二期作均以飼鴨處理稻穀產量最高，主要是因穗數的增加，稻穀產量對鴨子飼養密度呈二次曲線關係， Y （產量）= 620 + 58.58X - 0.1445X2，推薦最適（optimal）飼鴨密度為每公頃飼養202隻，可擭得最高稻穀產量。各雜草控制方法間對米飯食味總評無顯著差異。 綜合試驗結果顯示，紙膜敷蓋能有效控制雜草族群，但紙膜成本太高，且其成分是否符合有機農產品生產基準尚有疑慮。一期作利用滿江紅及黃豆粉敷蓋控制雜草也可以得到不錯的效果，且成本低。在水田裡飼養鴨子不僅能防除雜草，也會捕食昆蟲及福壽螺，降低蟲害、福壽螺危害及防治成本。

Field experiments were conducted from the second crop season of 2001 through the second crop season of 2002 on the paddy fields, to investigate effects of several weed control methods in organic farming. Experimental results of three continuous crops indicated that mulching of paper and ducks feeding had the highest weed control efficiency in the first crop of 2002. More than 99% weeds were controlled. The weed control efficiency of azolla and spreading with rice bran treatments were on the second rank. Experimental results of the second crop of 2002 showed that mulching of paper controlled weed with highest efficiency again. Duck treatment showed weed control efficiency as high as that 99.5% weeds were inhibited. Spreading of soybean meal (0.3 kg/m2) efficiently controlled the weed by 74.8%. Spreading of rice bran also controlled weed well with the application rate of 0.5 kg/m2. Yield of rice by duck treatment was the highest in the second crop of 2001, first and second crops of 2002, mostly owing to the increase of tiller and panicles of rice. The quadratic response for yield to ducks density was Y = 620 + 58.58 X - 0.1445 X2. Then the optimal input is suggested as 202 bird/ha. Experimental results indicated that mulching of paper control the weed population most efficiently. Since the cost is too expensive, and its composition meet the demand of regulation of organic farming, mulching of paper is still not recommend. Spreading of soybean meal also controlled weeds well and in low cost. Raising ducks in the paddy fields efficiently controlled the weeds and insects and Fu So Snail.