Household energy and recycling of nutrients and carbon to the soil in integrated crop-livestock farming systems: a case study in Kumbursa village, Central Highlands of Ethiopia
Household energy and recycling of nutrients and carbon to the soil in integrated crop-livestock farming systems: a case study in Kumbursa village, Central Highlands of Ethiopia
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DOI：
10.1111/gcbb.12459
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发表时间：
2017-10-01
影响因子：
5.6
通讯作者：
Gelana, Bogale
中科院分区：
文献类型：
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作者：
Negash, Dugassa;Abegaz, Assefa;Gelana, Bogale
在埃塞俄比亚高地，由于广泛使用粪饼和作物残渣作为燃料，用有机废物改良土壤的情况大大减少。这项研究评估了家庭能源和养分和碳循环到土壤之间的相互作用，采用家庭调查，焦点小组讨论，主要知情人访谈，直接观察和测量2014年至2015年在Kumbursa村（埃塞俄比亚中部高地）。所有接受调查的家庭都完全依赖生物质燃料做饭，生产和消费率与财富状况直接相关，这在三个农业财富群体（穷人，中等和富人）之间存在显着差异（P < 0.001）。作物残渣和粪饼占总生物质燃料消耗量的80（+/- 3）%（按能量含量计）和85（+/- 4）%（按干重计）。氮的平均损失为59（+/- 2）千克/公顷/年（每户109（+/- 8）公斤/年（-1）），13.9（+/- 0.3）千克公顷年磷（每户每年-1）26（+/-2）公斤），79（+/- 2）千克公顷年钾（每户每年150（+/- 11）公斤）和2100（+/- 40）公斤公顷（-1）年（-1）有机碳（每户每年3 000（+/- 300）公斤）。富裕的农民在燃料中损失的碳和营养物质明显多于其他财富群体的农民。然而，这些损失分布在更大的面积上，因此中等和贫穷农民的单位土地面积损失明显高于富裕农民。这意味着，由于燃料限制，较贫穷农民的土地可能比富裕农民的土地退化得更快，从而扩大了贫穷差距。由于不使用粪便和作物残留物作为有机肥料，估计每户家庭的经济损失为162（+/- 8）美元/年（-1）。然而，这低于其作为燃料的价值，为490（+/- 20）美元/年（-1）。因此，只有找到替代的、更便宜的燃料来源，才能说服农民使用这些有价值的资产作为土壤改良剂。
Soil amendment with organic wastes in the Highlands of Ethiopia has been greatly reduced by widespread use of dung cakes and crop residues as fuels. This study assessed the interaction between household energy and recycling of nutrients and carbon to the soil using household survey, focus group discussions, key informant interviews, direct observations and measurements between 2014 and 2015 in Kumbursa village (Central Highlands of Ethiopia). All surveyed households were entirely dependent on biomass fuel for cooking, with production and consumption rates directly related to wealth status, which significantly varied (P < 0.001) among three farm wealth groups (poor, medium and rich). Crop residues and dung cakes accounted for 80(+/- 3)% by energy content and 85(+/- 4)% by dry mass weight of total biomass fuel consumption. Mean losses were 59(+/- 2)kg ha(-1) yr(-1) nitrogen (109(+/- 8) kg yr(-1) per household), 13.9(+/- 0.3) kg ha(-1) yr(-1) phosphorus (26(+/- 2) kg yr(-1) per household), 79(+/- 2) kg ha(-1) yr(-1) potassium (150(+/- 11) kg yr(-1) per household) and 2100(+/- 40) kg ha(-1) yr(-1) organic carbon (3000(+/- 300) kg yr(-1) per household). Rich farmers lost significantly more carbon and nutrients in fuel than farmers in other wealth groups. However, these losses were spread over a larger area, so losses per land area were significantly higher for medium and poor than for rich farmers. This means that the land of poorer farmers is likely to become degraded more rapidly due to fuel limitations than that of rich farmers, so increasing the poverty gap. The estimated financial loss per household due to not using dung and crop residues as organic fertilizer was 162(+/- 8) US$ yr(-1). However, this is less than their value as fuels, which was 490(+/- 20) US$ yr(-1). Therefore, farmers will only be persuaded to use these valuable assets as soil improvers if an alternative, cheaper fuel source can be found.