Food and Agriculture Organization of the United Nations

SAVE AND GROW FARMING SYSTEMS FACT SHEET 9

MAIZE/FORESTRY Agro-ecological zone Tropical, rainfed Main cereal Where and shrubs Other crops/products Meat, milk, fodder, fuelwood cost less than fertilizer ood security in Malawi in the early rainy season and loses its leaves just as and Zambia depends field crops are being established; the leaves only grow on maize production. back at the end of the wet season. Maize can be grown However, in both directly under the leafless Faidherbia canopy, as the Fcountries, yields average a low trees do not compete with the crop for light, nutrients 1.2 tonnes per ha. Only about or water while the maize is growing. one in four smallholder farmers Thanks to the decaying leaves, the soil under the in Zambia and one in five in trees contains up to twice as much organic matter Malawi grow enough maize to and nitrogen as soil outside the canopy. There is also sell in markets. Since maize is a marked increase in soil microbiological activity, almost entirely rainfed, the crop is highly vulnerable and an increase in water holding capacity. Numerous to fluctuations in rainfall and temperatures, a studies have noted increases in yields when maize vulnerability that is likely to increase with climate is grown in association with Faidherbia, and those change. increases tend to be higher where soil fertility is One of the main obstacles farmers face in increasing low. In Zambia, maize planted outside the maize production is low soil fertility. Many maize canopy produced average yields of 1.9 tonnes per ha, farmers can neither afford mineral fertilizer nor compared to 4.7 tonnes when the crop was grown obtain sufficient amounts of organic fertilizer, such under the canopy; in Malawi, maize yields increased as animal manure. Decades of by 100 to 400 percent when the intensive cultivation without KEY POINTS crop was grown with Faidherbia. fertilization have drained Maize is practised on Both countries promote nutrients, particularly nitrogen, 300 000 ha in Zambia and half a million Faidherbia as part of conservation from the soil. in Malawi. agriculture (ca) systems that To address the problem, the By keeping native ‘fertilizer trees’ in their offer smallholder farmers a fields, farmers have boosted maize yields Zambia National Farmers’ Union by as much as 400 percent. means of increasing maize has explored ways of integrating productivity and earning higher Leguminous trees and shrubs add from nitrogen-fixing trees into maize 100 to 250 kg of nitrogen per ha to the incomes from sales. National production systems. The most soil in two to three years. recommendations are to grow promising candidate was found to Growing maize with leguminous shrubs 100 trees per ha in a 10 m x 10 m be Faidherbia albida, an African generates higher net returns than grid pattern. species with an unusual growing maize with subsidized mineral Faidherbia is now grown in growth habit. The tree is dormant fertilizer. conservation agriculture maize The system uses water more efficiently and is more resilient to drought. Agroforestry providesfuelwood and fodder, improves water filtration and sequesters carbon. systems covering some 300 000 ha in Zambia. In mineral fertilizer, subsidized or unsubsidized, for Malawi, there are about half a million farms with the continuous maize production. The study confirmed trees. Farmers have been able to establish most of that maize agroforestry is both socially profitable the Faidherbia stands simply by assisting the natural and financially competitive, compared to maize regeneration of tree seedlings on their land. production using only mineral fertilizer. Although Faidherbia is one of the fastest growing acacia species, it is not a quick fix for low soil fertility. Agroforestry practices have helped smallholder farmers In a survey of 300 Zambian farmers, one-third said overcome one barrier to the adoption of conservation that yields increased over a period of one to three agriculture: the lack of crop residues to maintain years, while 43 percent said that it took up to six years a constant soil cover. Because most African before they saw benefits in production. smallholders also raise , they often use crop residue biomass as animal fodder. With trees growing Planting leguminous coppicing trees, such as Gliricidia on their farms, there is now enough biomass to both sepium, which take less time to establish, is another meet livestock needs and improve maize yields. The way of increasing maize production trees also provide fuel for rural sustainably. On small landholdings Average yields of maize under and households – in Zambia, farmers in southern Malawi, the World outside Faidherbia albida canopy were able to gather 15 tonnes of Agroforestry Centre is promoting (t/ha) fuelwood per ha after the second a system in which farmers year of fallow with Sesbania and 5 • Gliricidia in rows in their maize Under 21 tonnes after the third year. fields, prune them back two or three Outside Agroforestry also improves soil times a year, and mix the leaves into 4 • structure and water filtration, the soil. Findings from a decade-long which makes farms more resilient study indicate that on unfertilized 3 • to drought. Moreover, it can play plots where Gliricidia is intercropped an important role in climate with maize, yields average 3.7 tonnes 2 • change mitigation. Conservation per ha, and reach 5 tonnes per ha agriculture with trees sequesters in good years. On unfertilized plots 1 • from 2 to 4 tonnes of carbon without Gliricidia, average yields were per ha per year, compared to 0.2 to 0 • only 0.5 to 1.0 tonne per ha. 2007/8 2008/9 2009/10 2010/11 0.4 tonnes under ca without trees. In areas where land holdings are In addition, by increasing maize larger than 1 ha, growing leguminous shrubs such production and the supply of fuelwood, farming as Sesbania sesban on fallow fields is another option systems that integrate trees with maize reduce the for revitalizing the soil and increasing maize yields. need for converting forests to farmland, which is a Leguminous trees and shrubs add from 100 to 250 kg major source of greenhouse gas emissions. of nitrogen per ha to the soil in fields that are left fallow for two or three years. Even though fields are Agroforestry does not require large investment. Low- unproductive for two out of every five years, returns income farmers are often quicker to embrace it than on investment are higher when maize is grown in farmers who are better off. Although more labour rotation with nitrogen-fixing shrubs and trees. is required initially, labour can be used more In eastern Zambia, one study found the average net efficiently once farmers master the new practices. profit was Us$130 per ha when farmers cultivated However, incorporating trees into crop production maize without fertilizer; Us$309 when it was grown is a knowledge-intensive activity. Policy support, in rotation with Sesbania; and Us$327 when it continued research and rural advisory services that was intercropped with Gliricidia. For each unit of engage smallholder farmers are crucial for the long- investment, farmers who integrated trees with maize term expansion of farming systems that integrate benefited from higher returns than those who used maize, shrubs and trees.

Adapted from: Contact Save and Grow in practice: maize, rice, wheat. Plant Production and Protection Division A guide to sustainable cereal production (FAO, 2016). Food and Agriculture Organization of the United Nations ISBN 978-92-5-108519-6 Viale delle Terme di Caracalla, 00153 Rome, Italy The book can be downloaded in PDF from: http://www.fao.org/3/a-i4009e.pdf [email protected] For a print copy, write to: [email protected] www.fao.org/save-and-grow © FAO, 2015 © FAO, I5312E/1/12.15