施用土壤改良劑對種植於酸性土壤落花生及水稻生產力之影響

Abstract

土壤因長期受到環境影響，如淋洗作用、風化作用、田間操作，施用化學肥料等，使土壤逐漸趨向酸化，因而對土壤中營養成份之有效性發生變化，甚者還會產生一些有害之金屬元素，不利於作物生長。台灣經調查80餘萬公頃耕地結果發現，pH值在5.5以下(屬強酸性土壤)已有28萬公頃，極需改良，以使農業能永續經營。為瞭解酸性土壤對落花生及水稻生理代謝之影響，分別取自花蓮縣瑞穗鄉及宜蘭縣礁溪鄉之強酸性土壤，以盆栽方式探討施用二種土壤改良劑(「FMP」及「副產石灰」)對土壤及對落花生及水稻生理代謝之影響，結果發現施用FMP作物收穫後土壤理化性之變化，旱田(種植落花生)土壤pH值可提高1.3∼1.5單位，水田(種植水稻)可提高1.1∼1.3單位，副產石灰在旱田可使土壤pH值提高1.3單位，水田亦可提高1.3單位。土壤有效磷含量可提昇5∼20 ppm，土壤有效性鉀、鈣含量下降，但下降程度較未經改良及空白兩處理為小，土壤有效性鎂下降程度較空白處理為低，對有害銅、鋅錳等含量下降程度則大於未經改良或空白處理。

A large area of agricultural land in Taiwan is covered by acid infertile soil and the area affected by acidity is increasing each year. Soil acidity factors adversely affect the survival, growth and production by increasing the availability of aluminum and manganese to toxin level, and by reducing the availability of phosphate. In order to realize the influence of acid soil on the growth of peanut [ Archis hypoga L.] and rice [Oryza sativa L.]. Soil sample were collected from two different place; Hualien and I-Lan which pH value are below 5.5. Samples of the soil, either mixed with two amendment materials containing PO4-2, Si, Ca and Mg (FMP); the other containing CaO and MgO (by-product of lime), or only chemical fertilize (check) and blank in pots (605x265x220 mm). From the results indicated that applying soil amendment “FMP” can elevated soil pH by an average of 1.3-1.5 and 1.1-1.3 for upland and paddy field, respectively. Lime soil can elevated soil pH by an average of -1.3 for both peanut and rice after harvest in whole experiment crop season. Soil available phosphate content increased 5-20 ppm and available calcium in soil increased slightly than control. Miner element such as magnesium and iron content in soil decreased slightly, while the toxin element copper and manganese decreased significantly than check. Plant growth in acid soil (check) exhibited poor characteristics, such as short plant height, less branch and pods per plant; small seed size and full-kernel percentage decreased significantly, same results showed for rice, especially root length was inhibited. The highest yield loss in acid soil (check) were 23% and 20% for peanut and rice, respectively due to lower nitrogen, phosphorus and potassium content in plants. At flowering (peanut) or heading ( rice) stage, the root activity was significant lower than the soil amendment “FMP” treatment in pots. In field test of peanut, 7 days after side dressing (FMP), then measured root activity showed that significantly higher than the blank. Peanut and rice in grown acid soil, from the soil sample and plant tissue analysis indicated that available phosphorus deficiency seems that was the main factor influence leaf chlorophyll content, so that the chlorophyll a/b ratio increased to influence the photosynthesis. From the analysis of changes in chlorophyll fluorescence emission results indicated that the paramaters Fv/Fm (the efficiency of excitation capture by open PSII reaction centers), Fsm (the maximal fluorescence in the steady-state lighr-adapted condition) and Yield (energy conversion) are lower than that soil amendment treatment. The results indicated soil amendment in acid soil was indeed very efficient to improve soil characteristics and plant photosynthesis ability on peanut and rice when they grew in acid soil.