施用不同比例稻殼生物炭及石灰搭配不同用量有機質肥料對土壤性質、落花生生育及產量之影響

落花生（Arachis hypogaea L.）為台灣中南部的重要經濟作物，同時也是少數台灣本地可充分供應的「食用油」來源，近年食安風波不斷，帶動國內花生油、花生的生產需求，同時也追求有機與健康的農產品。有機資材經由低氧高溫熱裂解，炭化後所產生之物質稱為「生物炭」。生物炭具有改善土壤理化性質，促進植株生長與提高作物產量的功能，其多孔隙之特性不但能保水與保肥，同時還能提供微生物棲息地。鹼性的石灰質材除了提升土壤pH值，間接增加土壤中養分的有效性，提升有益微生物活性，為酸性土壤改良方法中最經濟且效果最持久的策略。本試驗目的為藉由稻殼生物炭及石灰作為土壤改良劑，搭配有機質肥料用量探討對土壤性質、落花生生育及產量之影響。試驗採盆栽方式於2019年10月至2020年2月，在國立屏東科技大學永續農業研究農場的網室進行，試驗處理為施用不同量稻殼生物炭（0 %、2 %、4 % 與8 % （w/w））、不同量石灰（0.1 % 與 0.2 %（w/w））和不同量有機質肥料（含氮量為80 kg ha-1、160 kg ha-1、240 kg ha-1與 320 kg ha-1）。結果顯示隨著稻殼生物炭用量增加可顯著降低土壤總體密度，並增加土壤田間容水量，提高土壤pH值、EC值、有機質、Bray-1-P、交換性鉀、鈣與鎂含量，其中以交換性鉀含量提升效果最為明顯。施用有機質肥料之氮用量160 kg ha-1、240 kg ha-1與320 kg ha-1處理均顯著提高土壤理化性質，三個處理間則差異不顯著。植株乾物重則以石灰用量0.2 % 處理顯著高於其他處理，稻殼生物炭用量4 % 處理顯著高於其他稻殼生物炭處理，而施用8 % 稻殼生物炭用量處理則僅提高約1 %。施用苦土石灰可顯著提高土壤pH值、交換性鈣與鎂含量，顯著增加植體鎂濃度及鎂吸收量，對植株生育及產量則無顯著影響。有機質肥料之氮用量320 kg ha-1 之處理顯著提高植株乾物重。在8 % 稻殼生物炭處理用量，落花生籽實有較高的百粒重及收穫指數，總產量提高27 %，顯著高於對照組。施用稻殼生物炭增加始花期根部的N，顯著高於其他處理， 8 % 稻殼生物炭用量處理根部與地上部的P與K皆顯著高於其他處理，但收穫期地上部Ca顯著低於其他處理。綜合上述，增加稻殼生物炭、有機質肥料用量之應用的確能改善土壤理化性質，並以8 % 稻殼生物炭用量搭配有機質肥料之氮用量160 kg ha-1為最佳處理。

關鍵字

土壤改良劑；土壤肥力； pH值；土壤總體密度

並列摘要

Peanut（Arachis hypogaea L.）is an important economic crop in central and southern Taiwan, and it is also one of the few sources of "edible oil" that can be adequately supplied in Taiwan. In recent years, food safety disturbances have continued to drive domestic demand for peanut oil and peanut production, while also pursuing organic and healthy agricultural products. Organic materials are carbonized by low-oxygen and high-temperature thermal pyrolysis, which is called "biochar". Biochar has the functions of improving soil physical and chemical properties, promoting plant growth and increasing crop yield. Its porous properties can not only retain water and fertilizer, but also provide microbial habitat. Lime materials not only increase the pH of the soil, but also indirectly increase the availability of nutrients in the soil and increase the activity of beneficial microorganisms. This is the most economical and long-lasting strategy in acid soil improvement methods. The purpose of this experiment is to use rice husk biochar and lime as soil amendments, combined with the amount of organic fertilizer to explore the effects on soil properties, growth and yield of peanut. The experimental potting method was from October 2019 to February 2020 in the net room of the National Pingtung University of Science and Technology Sustainable Agriculture Research Farm. The experimental treatment was to apply different amounts of rice husk biochar（0 %, 2 %, 4 % and 8 %（w/w））, lime （0.1 % and 0.2 %（w/w））and organic fertilizers（nitrogen content of 80 kg ha-1, 160 kg ha-1, 240 kg ha-1 and 320 kg ha-1）. The results showed that the increase in the amount of rice husk biochar can significantly reduce the bulk density of the soil, increase the soil moisture content in the field, and increase the soil pH, EC, organic matter, Bray-1-P, exchangeable potassium, calcium, and magnesium content. The effect of increasing exchangeable potassium content is the most obvious. The application of organic fertilizer with a nitrogen rate of 160 kg ha-1 , 240 kg ha-1, and 320 kg ha-1 significantly improves the physical and chemical properties of the soil, but there was no significant difference among the three treatments.. The dry weight of the plant was significantly higher than other treatments with a lime dosage of 0.2 %. The rice husk biochar dosage of 4 % was significantly higher than other rice husk biochar treatments, while the 8 % rice husk biochar dosage was only increased by about 1 %. The application of lime can significantly increase the soil pH value, exchangeable Ca and Mg content, significantly increase the Mg concentration and Mg absorption of the plant, but has no significant effect on plant growth and yield. The treatment of 320 kg ha-1 of organic fertilizer nitrogen significantly increased plant dry weight. At 8 % rice husk biochar treatment dosage, peanut seeds actually have a higher 100-grain weight and harvest index, and the total yield increased by 27 %, which was significantly higher than the control group. The application of rice husk biochar increased the N in the root at the initial flowering stage, which was significantly higher than other treatments. The P and K in the roots and shoots of the 8 % rice husk biochar treatment were significantly higher than those of other treatments, but the Ca in the shoots at harvest was significantly lower than that of other treatments. Based on the above, the application of increasing the amount of rice husk biochar and organic fertilizer can indeed improve the physical and chemical properties of the soil, and the best treatment is to use 8 % of the rice husk biochar with the organic fertilizer nitrogen amount of 160 kg ha-1.