Laboratory of Soil Ecology, Cinvestav, Mexico D.F., México.
Sci Total Environ. 2010 Oct 1;408(21):4961-8. doi: 10.1016/j.scitotenv.2010.07.024. Epub 2010 Aug 6.
In a previous laboratory experiment, extracts of neem (Azadirachta indica A. Juss.) and Gliricidia sepium Jacquin, locally known as mata-raton, used to control pests on crops, inhibited emissions of CO(2) from a urea-amended soil, but not nitrification and N(2)O emissions. We investigated if these extracts when applied to beans (Phaseolus vulgaris L.) affected their development, soil characteristics and emissions of carbon dioxide (CO(2)) and nitrous oxide (N(2)O) in a greenhouse environment. Untreated beans and beans planted with lambda-cyhalothrin, a commercial insecticide, served as controls. After 117days, shoots of plants cultivated in soil amended with urea or treated with lambda-cyhalothrin, or extracts of neem or G. sepium were significantly higher than when cultivated in the unamended soil, while the roots were significantly longer when plants were amended with urea or treated with leaf extracts of neem or G. sepium than when treated with lambda-cyhalothrin. The number of pods, fresh and dry pod weight and seed yield was significantly higher when bean plants were treated with leaf extracts of neem or G. sepium treatments than when left untreated and unfertilized. The number of seeds was similar for the different treatments. The number of nodules was lower in plants fertilized with urea, treated with leaf extracts of neem or G. sepium, or with lambda-cyhalothrin compared to the unfertilized plants. The concentrations of NH(4)(+), NO(2)(-) and NO(3)(-) decreased significantly over time with the lowest concentrations generally found at harvest. Treatment had no significant effect on the concentrations of NH(4)(+) and NO(2)(-), but the concentration of NO(3)(-) was significantly lower in the unfertilized soil compared to the other treatments. It was found that applying extracts of neem or G. sepium leaves to beans favored their development when compared to untreated plants, but had no significant effect on nitrification in soil.
在之前的实验室实验中， locally known as mata-raton 的印楝（Azadirachta indica A. Juss.）和葛藤（Gliricidia sepium Jacquin）的提取物被用于控制作物上的害虫，抑制了尿素改良土壤的 CO(2)排放，但不抑制硝化和 N(2)O 排放。我们研究了当这些提取物应用于豆类（Phaseolus vulgaris L.）时是否会影响其生长、土壤特性以及温室环境中二氧化碳 (CO(2))和氧化亚氮 (N(2)O)的排放。未处理的豆类和种植了商业杀虫剂 lambda-氯氟氰菊酯的豆类作为对照。在 117 天后，与未施肥土壤相比，用尿素改良土壤或用 lambda-氯氟氰菊酯处理或用印楝或葛藤叶提取物处理的植物，其植株的地上部分显著更高，而根系则显著更长。与用 lambda-氯氟氰菊酯处理相比，用尿素改良土壤或用印楝或葛藤叶提取物处理的植物的豆荚数量、新鲜和干燥豆荚重量以及种子产量均显著更高。用印楝或葛藤叶提取物处理的植物的种子数量与未处理和未施肥的植物相似。与未施肥的植物相比，用尿素施肥、用印楝或葛藤叶提取物处理或用 lambda-氯氟氰菊酯处理的植物的根瘤数量较低。随着时间的推移，NH(4)(+)、NO(2)(-)和 NO(3)(-)的浓度显著下降，通常在收获时浓度最低。处理对 NH(4)(+)和 NO(2)(-)的浓度没有显著影响，但与其他处理相比，未施肥土壤的 NO(3)(-)浓度明显较低。研究发现，与未处理的植物相比，将印楝或葛藤叶提取物应用于豆类有利于其生长，但对土壤硝化没有显著影响。
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