一項研究說,，多樣化的谷物種植可能有助于增強非洲的可持續(xù)糧食安全。許多非洲國家面臨糧食短缺,，這部分是由于正在退化的生態(tài)系統(tǒng)帶來的農(nóng)業(yè)生產(chǎn)力的下降,。Sieglinde S. Snapp及其同事探索了種植豆類植物的作物多樣化而非單一栽培是否能為馬拉維帶來可持續(xù)谷物生產(chǎn)，馬拉維是一個總體說來有1300萬人口的貧困國家，一些人把它稱贊為非洲綠色革命的誕生地,。
政府對化肥和優(yōu)良玉米種子的補貼已經(jīng)讓馬拉維無數(shù)農(nóng)民的生產(chǎn)力取得了顯著收益,。但是廣泛存在的單一種植玉米的做法，再加上該國對富含熱量的食品的不斷增長的需求,，已經(jīng)在無意之間導(dǎo)致了與單一栽培有關(guān)的農(nóng)業(yè)生產(chǎn)力的不穩(wěn)定,。
這組作者既進行了一場多樣化玉米種植的全國范圍試驗，也進行了旨在了解農(nóng)民對多樣化農(nóng)業(yè)的評估的參與式研究項目,。這組作者發(fā)現(xiàn)，間作和輪作灌木狀的豆科植物能幫助增加固氮,，減少對化肥的需求,，并增加有營養(yǎng)的谷物的產(chǎn)量。這組作者說,，這些發(fā)現(xiàn)提示,，多樣化的谷物種植可能幫助提高非洲的糧食和環(huán)境安全。（生物谷Bioon.com）
生物谷推薦英文摘要：
PNAS doi: 10.1073/pnas.1007199107
Biodiversity can support a greener revolution in Africa
Sieglinde S. Snappa,1, Malcolm J. Blackieb, Robert A. Gilbertc, Rachel Bezner-Kerrd, and George Y. Kanyama-Phirie
The Asian green revolution trebled grain yields through agrochemical intensification of monocultures. Associated environmental costs have subsequently emerged. A rapidly changing world necessitates sustainability principles be developed to reinvent these technologies and test them at scale. The need is particularly urgent in Africa, where ecosystems are degrading and crop yields have stagnated. An unprecedented opportunity to reverse this trend is unfolding in Malawi, where a 90% subsidy has ensured access to fertilization and improved maize seed, with substantive gains in productivity for millions of farmers. To test if economic and ecological sustainability could be improved, we preformed manipulative experimentation with crop diversity in a countrywide trial (n = 991) and at adaptive, local scales through a decade of participatory research (n = 146). Spatial and temporal treatments compared monoculture maize with legume-diversified maize that included annual and semiperennial (SP) growth habits in temporal and spatial combinations, including rotation, SP rotation, intercrop, and SP intercrop systems. Modest fertilizer intensification doubled grain yield compared with monoculture maize. Biodiversity improved ecosystem function further: SP rotation systems at half-fertilizer rates produced equivalent quantities of grain, on a more stable basis (yield variability reduced from 22% to 13%) compared with monoculture. Across sites, profitability and farmer preference matched: SP rotations provided twofold superior returns, whereas diversification of maize with annual legumes provided more modest returns. In this study, we provide evidence that in Africa, crop diversification can be effective at a countrywide scale, and that shrubby, grain legumes can enhance environmental and food security.
