Akello, J.

Alamu, E.O.

Chikoye, D.

Dale, L.

Mehreteab, T.

Nagothu, U.S.

Ngumayo, J.

Njoloma, J.

Nyoka, I.

Ray, C.

Alamu, Emmanuel Oladeji

Chikoye, David

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1International Institute of Tropical Agriculture (IITA), Southern Africa Hub, Lusaka, Zambia 2International Centre for Research in Agroforestry (ICRAF), Lilongwe, Malawi3Community Markets for Conservation (COMACO), Lusaka, Zambia 4Norwegian Institute of Bioeconomy Research (NIBIO), Norway Impacts of Agroforestry conservation practiceson soil health, crop nutrients and safety in ZambiaAlamu Emmanuel Oladeji1, Njoloma Joyce2, Ngumayo Joel3, Akello Juliet1, Chikoye David1, Nyoka Isaac2, Dale Lewis3, Ray Chazangwe3, Mehreteab Tesfai4, and Nagothu Udaya Sekhar4www.iita.org   I   www.cgiar.org IntroductionThe current farming systems rely heavily on the intensive use of external resourcesand inputs such as water, mineral fertilizers, and pesticides to increase agriculturalproductivity (Bernard and Lux, 2017) while negatively impacting the soil & othernatural resources. The uptake and utilization of the soil nutrients are essential forensuring proper growth and improving crop yield and quality. Soil health and cropnutrition could be improved by incorporating green leaf biomass of leguminous treessuch as Gliricidia sepium in agroforestry systems (Fig 1). It is assumed thatcombining maize-legume-agroforestry conservation practices with Gliricidia couldprovide multiple benefits and reduce production risks to smallholders. A multi-disciplinary Gliricidia project was established to explore the assumption by involvingsmallholder farmers in two maize growing districts in Eastern Zambia. A commonpractice in the study area is mulching using Gliricidia leaf biomass.AcknowledgementsThe authors acknowledge the financial support from NORAD and the support of allfarmers that participated in the studyOur research findings• Maize yield from the control plots (T3) was lower (1.2 t/ha) than T1 (4.5 t/ha) and T2 (6.0 t/ha).• The soil organic carbon (SOC) content of the sampled soils ranged from 0.32% (0.60% organicmatter, OM) to 1.10 % (2.0% OM), which is very low despite some positive increase observedsince the incorporation of Gliricidia leaf manure (Fig 3) into the treated soils (T1, T4, T5).• The soil bulk density (BD) ranged between 1.26 and 1.36 g/cm3, within 1.0 to 1.7 g/cm3 fortypical agricultural soils (Brady and Weil, 2002).• The treatments intercropped with Gliricidia (T1, T4, T5) showed, in general, higher ash, totalcarbohydrate, starch, amylose, and crude fibre contents than the controls: sole maize (T2with fertilizer, T3 without fertilizer), soybean (T6) and groundnuts (T7).• Gliricidia intercropping significantly (p<0.05) reduced the tannin and phytic contents insoybean, groundnuts, and maize grains. Moreover, Gliricidia increased the nitrogen contentin the grains, resulting in increased protein content (Fig 4).ConclusionCrop diversification through intercropping of cereals with legumes and intercropping withGliricidia trees enhanced diversity (in crops, trees, habitat, healthy food diets, markets), synergies(combining annual & perennial plants), resilience (to climate change) and culture and foodtraditions (increasing healthy food production & consumption and supporting the right toadequate food). Gliricidia incorporation increased the soil organic matter, improved the nutritionalquality and reduced the mycotoxin prevalence. Policy and institutional support are needed toincrease the adoption of agroforestry systems with Gliricidia trees by smallholder farmers.ObjectivesThe study's primary objectives were to(i) monitor the soil and crop nutrients(e.g., Nitrogen, Organic Carbon) andmeasure crop yields underagroforestry systems (e.g., Gliricidiasepium) at different levels ofintensification and land degradation.(i) assess the impact of agroforestry-based interventions on the nutrientsof the selected food crops todetermine if agroforestry practicesresult in healthier and nutrient-richcrop produce.ReferencesBernard, B. and Lux, A. (2017) 'How to feed the world sustainably: an overview of the discourseon agroecology and sustainable intensification', Reg Environ Change, vol. 17, pp.1279–1290.Brady, N.C. and Weil, R. R (2002) 'The Nature and Properties of Soils', 13th Edition, Prentice-Hall,NJ; 960 p; ISBN: 13-016763-0.Figure 2: 2D plots design for the trialFigure 1: Gliricidia incorporation into the soil (credit-Njoloma Joyce)Table 1:  Effects of Gliricidia and mineral fertilizer application on mycotoxin (aflatoxin, ppb)  prevalence in maize and groundnut. 05101520253000.20.40.60.811.21.41.6T1 T2 T3 T4 T5 T6 T7Carbon stock (t/ha)OC (%);BD (Mg/cm3)TreatmentOC (%) BD (Mg/m3) C Stock (t/ha)Figure 3:   Mean Organic carbon, BD and carbon stock estimates from the seven treatment plotsFigure 4: Effects of treatment on the nutritional & antinutritional properties of (a) maize, (b) soybean, and (c) groundnuts.E-mail address of the presenting authoro.alamu@.cgiar.org Results and DiscussionCredit-Njoloma JoyceFarmer-led field trials were establishedin 15 sites with seven treatments (T) thatincluded Gliricidia intercropping withmaize, soybean and groundnuts andcontrol (sole crops)(Fig 2). Over the lasttwo growing seasons, crop(179) andsoil(360) samples were collected andanalyzed for: i) nutritional,antinutritional, functional, and mineralproperties, as well as mycotoxin(aflatoxin and/or fumonisin) andAspergillus load (crops); and ii) soilnutrients and microbial loads.Materials and Methods• Gliricidia incorporation had minimal effect on the occurrence and distribution of Aspergillusspp. in the soils and crops. Overall, treatments with Gliricidia recorded lower mycotoxinprevalence, while sole maize (T3) registered the highest mycotoxin prevalence (Table 1).• There was a higher prevalence of mycotoxins in Gliricidia plots than in sole groundnuts ingroundnuts.• Various multimedia platforms, including social media, were used to disseminate informationon Gliricidia agroforestry practices and their benefits to farmers and others.

Impacts of Agroforestry conservation practices on soil health, crop nutrients and safety in Zambia

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Impacts of Agroforestry conservation practices on soil health, crop nutrients and safety in Zambia

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