Chemical properties and soil organic matter assessment under fallow systems in the forest margins benchmark
Chemical properties and soil organic matter assessment under fallow systems in the forest margins benchmark
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林缘基准休耕制度下的化学性质和土壤有机质评估
DOI：
10.1016/s0038-0717(02)00005-6
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发表时间：
2002
影响因子：
9.7
通讯作者：
S. Weise
中科院分区：
文献类型：
--
作者：
L. Koutika;N. Sanginga;B. Vanlauwe;S. Weise
在西非和中非潮湿森林地区，休耕管理在为生长中的作物提供养分、抑制杂草、减少病虫害以及提高种植制度的可持续性方面发挥着关键作用。我们评估了天然葛根休耕和不含葛根的休耕（手工去除葛根）下的土壤养分浓度、土壤酸度和土壤有机质状况，并在喀麦隆南部三个不同土壤理化性质的不同地点种植葛根。北部样地人口压力大，休耕时间短，中部样地处于中间状态，南部样地则相反。北部站点砂质粘土的养分浓度（Ca2+和Mg2+）和有效阳离子交换容量（ECEC）最高。中部站点的沙质土壤的Al饱和度和土壤酸度最低，而南部站点的粘性土壤的养分浓度ECEC最低，土壤酸度和Al饱和度最高。葛根降低了土壤酸度，提高了土壤养分浓度。葛根对土壤酸度和养分浓度的有益影响在中部地区不太明显，在南部地区则没有。在北部和中部，葛根下玉米产量最高，表明玉米对氮的响应性。在颗粒有机质（POM） （53 ~ 4000μm）质量较小（<1.50mg / g）、化学约束较大（土壤酸度和铝饱和度高）的南部土壤，葛根下中（250 ~ 2000μm）和细（53 ~ 250μm） POM的氮含量高于自然休耕。葛根中POM土壤中氮含量比自然休耕提高47%。葛根下细粒POM中N含量比自然休耕高59%。在南部地区，化学约束导致所有休耕类型的玉米产量都很低。对玉米而言，POM质量（即N含量）比POM数量（即重量）更重要，而花生和木薯对POM数量更为敏感。葛根在低酸性土壤中具有良好的生态和环境可持续性，而在酸性土壤中，毛臭草似乎比葛根更具可持续性。然而，在这项研究中发现的作物产量很低。玉米产量低于2000kgha−1，花生籽粒干物质产量低于600kgha−1，木薯块茎干物质产量低于400kgha−1。因此，为了达到最高的生产力水平，有必要将休耕管理（主要种植葛根，即使在存在化学限制或土壤退化的情况下也能增加氮含量）与肥料（有机和矿物）的使用结合起来。
Fallow management plays a key role in supplying nutrients to the growing crop, suppressing weeds, reducing pests and diseases, and improving the sustainability of cropping systems in the humid forest zone of West and Central Africa. We evaluated soil nutrient concentration, soil acidity and soil organic matter status under natural Chromolaena fallow, fallow without Chromolaena (where Chromolaena was removed by hand), and planted Pueraria fallow in three different sites with different soil physico-chemical properties in southern Cameroon. Human population pressure is high and fallow length is short in the northern site, while an intermediate position and the contrary were observed in the central and southern sites, respectively. The highest nutrient concentrations (Ca2+and Mg2+), and effective cation exchange capacity (ECEC) were found in the sandy clayey soils in the northern site. The lowest Al saturation and soil acidity were noticed in the sandy soils in the central site, while in the clayey soils in the southern site the lowest nutrient concentration, ECEC, and the highest soil acidity and Al saturation were found. Pueraria decreased soil acidity and increased nutrient concentration relative to Chromolaena in the northern site. The beneficial effects of Pueraria on soil acidity and nutrient concentration became less pronounced in the central site and were absent in the southern site. In the northern and central sites, the highest maize yield was observed under Pueraria, showing the responsiveness of maize to N. In the soils of the southern site with the smaller weight (<1.50mg per g of soil) of particulate organic matter (POM) (53–4000μm) and greater chemical constraints (high soil acidity and Al saturation), higher in N content in medium (250–2000μm) and fine (53–250μm) POM was found under Pueraria compared to natural fallow. N content in medium POM under Pueraria was greater by 47% compared to the natural fallow. The N content in fine POM under Pueraria was greater by 59% relative to the natural fallow. In the southern site, chemical constraints induced very low maize yields under all fallow types. It appears that POM quality, i.e. N content, was more important for maize than POM quantity, i.e. weight, while groundnut and cassava were more sensitive to POM quantity. Pueraria have a beneficial ecological and environmental sustainability in the soil with low acidity, while Chromolaena seems to be more sustainable than Pueraria in the acidic soils. However, crop yields found in this study were low. Maize yield was lower than 2000kgha−1, groundnut grain dry matter yield was lower than 600kgha−1and cassava was lower than 400 tuber dry matter kgha−1. Therefore, to attain, highest productivity levels it is necessary to combine fallow management (primarily planted such as Pueraria which can increase N content even where there are chemical constraints or soil degradation) with the use of fertilisers (organic and mineral).