Hands Michael
Department of Geography, University of Cambridge, Downing Place, Cambridge CB2 3EN, UK.
Inga Foundation, Higher Penhale, Lostwithiel, Cornwall PL22 0HY, UK.
R Soc Open Sci. 2021 Feb 17;8(2):201204. doi: 10.1098/rsos.201204.
This account describes the context, history and outcomes of a series of studies into the ecology of slash-and-burn (S-B) agriculture in the world's humid tropics. These studies, which began in the mid-1980s, identified promising lines of research and continued to field trials, in Central America, of candidate agricultural systems as possible sustainable alternatives to the practice. The only system to emerge from 7 years' comparative trial with any promise of sustainability, in this context, was the agroforestry technique known as alley-cropping; but only with trees of the genus . Inga alley-cropping then underwent field trials with subsistence farming families in northern Honduras. The system was aimed at the twin objectives of achieving food security in basic grains, on minimal inputs, and of providing the means of eliminating further S-B in the region. Since then, Inga alley-cropping has become the heart of a sustainable and integrated rural livelihood model (the Guama Model) which is being implemented successfully in northern Honduras with some 300 families. These families had been attempting to subsist on a few hectares of land degraded by decades or centuries of S-B. The development of Inga alley-cropping, supplemented by rock phosphate and other mineral supplements, as a sustainable subsistence and cash crop alternative means that land previously being held in reserve for subsequent S-B operations can now be planted to permanent forms of agroforestry. Entire landscapes can be re-greened by productive agroforest vegetation. Achieving this at scale will require the investment of huge extension effort and funds. However, the environmental, social and economic returns are also huge; and they are sustainable. In this programme,we are seeing the vitality and goodwill of hundreds of families focussed on the raising, planting and management of trees in ways that feed the living organisms of the soil and, hence, feed themselves. In so cheerfully planting out their own futures, they plant and reshape the future of their own country. Replicating this at scale, as Rattan Lal outlines below, could reshape the future of this planet. In the mid-1980s, progress on sustainable alternatives to S-B, especially in rain forests, was frustrated by a lack of conclusiveness in the literature as to why soil fertility fails so rapidly post-burn; but also by a degree of contradiction on the impacts of the burn on certain plant nutrients. Hands (Hands 1988 The ecology of shifting cultivation. MSc thesis, University of Cambridge) concentrated on the role of soil phosphorus and attempted to resolve these contradictions. The Cambridge Alley-cropping Projects (1988-2002) continued this theme and threw light on the question of sustainable food production in rain forest environments.
本报告描述了一系列关于世界湿润热带地区刀耕火种农业生态研究的背景、历程和成果。这些研究始于20世纪80年代中期，确定了有前景的研究方向，并在中美洲继续对候选农业系统进行田间试验，以期找到可替代刀耕火种农业的可持续方法。在此背景下，经过7年比较试验，唯一有望实现可持续性的系统是一种名为 alley-cropping 的农林业技术；但仅适用于印加属树木。随后，印加 alley-cropping 在洪都拉斯北部的自给农民家庭中进行了田间试验。该系统旨在实现两个目标：以最少投入实现基本谷物的粮食安全，并提供消除该地区进一步刀耕火种的手段。从那时起，印加 alley-cropping 已成为一种可持续且综合的农村生计模式（瓜马模式）的核心，该模式正在洪都拉斯北部约300个家庭中成功实施。这些家庭此前一直试图在因数十年或数百年刀耕火种而退化的几公顷土地上维持生计。印加 alley-cropping 的发展，辅以磷矿粉和其他矿物质补充剂，作为一种可持续的自给和经济作物替代方式，意味着以前为后续刀耕火种作业预留的土地现在可以种植永久性的农林业作物。整个景观可以通过高产的农林业植被重新变绿。大规模实现这一目标需要投入大量的推广努力和资金。然而，环境、社会和经济回报也非常巨大；而且是可持续的。在这个项目中，我们看到数百个家庭的活力和善意，他们专注于树木的种植、培育和管理，以滋养土壤中的生物，进而养活自己。他们如此愉快地为自己的未来播种，也在种植和重塑自己国家的未来。正如拉坦·拉尔在下文所概述的，大规模复制这一模式可能会重塑这个星球的未来。在20世纪80年代中期，寻找刀耕火种农业可持续替代方法的进展，尤其是在雨林地区，因文献中对于为何刀耕火种后土壤肥力迅速下降缺乏定论而受阻；同时，对于刀耕火种对某些植物养分的影响也存在一定程度的矛盾观点。汉兹（汉兹，1988年，《轮垦农业生态学》，剑桥大学硕士论文）专注于土壤磷的作用，并试图解决这些矛盾。剑桥 alley-cropping 项目（1988 - 2002年）延续了这一主题，并阐明了雨林环境中可持续粮食生产的问题。
