有機質肥料在有機農耕法土壤中之轉形、殘效及作物吸收效率(III)

Abstract

(一)比較生態管理下，有機、折衷及慣行三種農耕法對土壤及銅、鋅累積量變動之影響。 (二)本研究為研發區別有機及化學肥料農耕蔬菜之偵測技術,已建立蔬菜汁取出導管液之方法及正申請專利中。經盆栽及田間栽培化學肥、有機肥及衷中三種方式之蔬菜,分析氟、氯、硝態氮及硫酸根陰離子之結果顯示無法區分三種不同栽培之蔬菜,但以高效液相層析儀(HPLC)分析有機酸時,顯示可區分有機及衷中栽培與化學肥之栽培之蔬菜,將可提供進一步研究及應用。 (三)有機質肥料的施用具有多重的優點，唯不適當的施用亦會造成負面的效應，本研究即在建立配合有機質肥料特性和土壤性質的有機質肥料管理策略，以降低對環境品質的衝擊。 (四)在高雄區農業改良場旗南分場之長期有機栽培示範田進行研究，探討1、不同輪作制度下，2、不同有機堆肥用量下，與3、不同有機堆肥種類下各種蔬果等作物可食部份硝酸態氮與亞硝酸氮含量與分佈之影響。了解不同種類有機肥料長期施用，與施用量對各種蔬果等作物可食部份硝酸態氮與亞硝酸氮含量之影響。並了解環境因子與有機肥料對植體硝酸態氮與亞硝酸氮含量之交感作用，提供降低作物硝酸態氮與亞硝酸氮含量之有機肥培方法。 (五)氮素是作物生長所需的重要元素，土壤中氮素含量的多寡會影響到作物的生長。由於台灣處於亞熱帶易變的海島型氣候，氮素在土壤中的變化很大。為求土壤中氮素肥力能持續維持以供作物吸收利用，實有需探討有機農法中有機肥料的施用對土壤中氮素的轉化、銨離子固定與釋放、硝酸態氮在土壤中的保持與流失及作物吸收等之影響。其中尤其是固定態銨方面的研究，固定態銨在土壤氮素循環圈中扮演一重要的角色。土壤對銨離子的固定不但可當作氮素的儲存庫，且可供作物生長時持續性地吸收和利用，如此也可避免土壤因過多的硝酸根與亞硝酸根被淋洗出來所造成的地下水污染與毒害問題。 (六)有機肥提供植物生長所需養分，但不當施用引起土壤劣化。本研究在明瞭有機栽培農戶有機質肥料的使用現況、土壤品質、肥料利用率及養分不均衡境況，然後田間試驗擬定合理減少及平衡的肥料施用策略。26個有機農田表土分析顯示，硝酸態氮、Olsen磷、Bray-1磷、交換性鉀、鈣、鎂、鈉多過量。其中磷肥最嚴重，鉀鈣鎂之絕對值偏高，相對鈣鎂多而鉀少。田間葉菜栽培5作，肥料利用率隨堆肥用量增加而降低；氮、磷利用率低，鉀則高；低用量(5.7與8.5 t/ha)的鉀肥利用率超過堆肥提供的鉀量；土壤鉀、鎂、鈉的當量百分比因施堆肥而提高，鈣則降低。

1.The effect of organic farming on soil properties and crops in agroecosystem and evaluation of Cu and Zn leftover in soils.: The purpose of this study is to investigate the effect of organic farming on soil properties and crops in agroecosystem. Field trial are setting at Chishan, Kao-Hsiung county, The test field including in an agroecosystem, whole area use biological control method to manage the pest and weed instead of pesticides. In this study, we sampling at harvest period, for measurement soil physical-chemical property, determination of soil biomass nitrogen and soil biological activity. And N, P, K, Ca, Mg, Cu and Zn content of plant harvested protion, leaf with stem, and root apply animal dung compost as fertilizer to produce crops. may make excessive copper and zinc leftover in soil. At harvest period, take soil and crop sample to measure the amounts of copper and zinc leftover in soil, estabilish the copper and zinc loading rate for each year application of animal dung compost in different soils and cropsystem.

2.Detective method for vegetable of organic and chemical farmings: This project tries to develop a method to distinguish chemical and organic farming vegetables. The technique to get vegetable sap from xylem was established. From pot and field cultivated vegetables, the results showed that F- , Cl , NO3- and SO4-2 anions in chemical, organic and mixed fertilizations were not significantly different, but the chromatograms of organic acids in HPLC analysis were significantly different . We will further to do more experiment to confirm the result.

3. The development of application technique of organic fertilizers for reducing the impact on environmental quality(II) The use of organic fertilizers has multiple benefits, however, there are some negative effects resulted from unsuitable application of organic fertilizers. The purpose of this study is to develop a management practice of organic fertilization matching the characteristics of organic fertilizer and soil in order to reduce the impact on environmental quality. 4. The purpose of this study is to investigate the plant nitrate and nitrite contents under long-term application of various organic fertilizers at different rates. The interactions within environmental factors and fertilization on plant nitrate and nitrite contents are also be determined.

5.Effects of Different Organic Fertilizers on Transformation and Mobility of Nitrate N in Soils: Nitrogen is an important element of crop nutrition during growing. Amounts of soil nitrogen can affect growth of crops. The variation of soil nitrogen was very large due to Taiwan was an island with easily changeable climate. We must study effects of applying organic fertilizers in organic agricultural farming on transformation of nitrogen, fixation and release of ammonium, retention and leaching of nitrate N and uptake of crops in soils. Especially, it is an important research about ammonium fixation, and fixed ammonium play an important role in nitrogen cycle of soils. Ammonium fixation could be looked as a pool of soil nitrogen and fixed ammonium could be absorbed and used by crops during growth, and that will avoid pollution of ground water and toxic problems due to over amounts of nitrite and nitrate were leached from soils.

6.The Studies of Balancing Soil Nutrients in Organic Fertilizers Application: Organic amendments can be valuable resources of many nutrients for plant growth. But soil degradation caused by unsuitable application. The objects of this study were to investigate the organic fertilizer