Spatial rooting patterns of gliricidia, pigeon pea and maize intercrops and effect on profile soil N and P distribution in southern Malawi
Makumba, W. ; Akinnifesi, F.K. ; Janssen, B.H. - \ 2009
African Journal of Agricultural Research 4 (2009)4. - ISSN 1991-637X - p. 278 - 288.
nitrogen dynamics - agroforestry systems - cropping systems - west-africa - tree - sepium - productivity - competition - prunings - biomass
The concept of competition or complementarity between tree and crop roots for below ground resources have been a major debate in simultaneous systems. Root studies were conducted in three cropping systems, namely: sole maize, pigeon pea/maize intercropping and Gliricidia sepium (Gliricidia)/maize intercropping, with the objective of understanding the potential for competition or otherwise. Pigeon pea and maize root development was monitored at 21, 42 and 63 days after planting (DAP). Also soil mineral N and Olsen P were assessed along the soil profile up to 200 cm depth. Maize roots developed faster than those of pigeon pea during the first 42 days after planting and there was little overlapping of maize and pigeon pea roots. However, the roots of both pigeon pea and maize had its peaks at 63 DAP, suggesting potential competition during reproductive growth stage of maize. In Gliricidia/maize intercropping, maize had the highest root density averaging 1.02 cm cm(-3) in the top 0 -4 0 cm soil layer, whereas gliricidia had lower root length density (0.38 cm cm(-3)) in the top 0 - 40 cm soil layer compared to 0.65 cm cm(-3) in the subsoil (40 - 100 cm). In Gliricidia/maize intercropping, mineral N was increased by 34 - 44 kg ha(-1) in the 0 - 100 cm soil layer, whereas Olsen P decreased by 32 kg ha(-1) in the entire 0-200 cm soil profile compared to the sole maize plot. Pigeon pea may be the "loser" in an association that involved both maize and Gliricidia. Because maize had more roots growing within 0 40 cm soil layer than Gliricidia it is able to take advantage of the nutrients from the applied Gliricidia prunings in the ridges. The study confirmed root compatibility between Gliricidia and maize and nutrient pumping from deep soil layers.
Optimization of Nitrogen released and immobilization from soil-applied prunings of Sesbania sesban and maize stover
Makumba, W. ; Akinnifesi, F.K. ; Janssen, B.H. ; Oenema, O. - \ 2007
Scientific research and essays 2 (2007)9. - ISSN 1992-2248 - p. 400 - 407.
mineralization - decomposition - availability - leucaena - quality - leaves - malawi - trees
A glasshouse experiment was conducted using the double-pot technique involving mixtures of low and high quality N sources with the objectives of determining 1) N mineralization and substitution value of high quality organic materials, 2) N immobilization by low quality maize stover, and the subsequent remineralization of immobilized N, and 3) N mineralization from or immobilization by mixtures of high and low quality organic materials. The experiment was designed in a 6 x 3 factorial combinations of sources of easily available N ( inorganic fertilizer and Sesbania sesban) with a source of low level of available N ( maize stover). The six levels of easily available N were 0, 50, 100 and 150 mg N per pot in the form of NH4NO3-N, and about 34 and 136 mg organic N per pot with S. sesban prunings. The levels of maize stover were 0, 2.5 and 5.0 g per pot. Application of 2.5 and 5 g maize reduced maize biomass yield by 4 and 16%, and N immobilization by 18-24% of added equivalent fertilizer N at 28 days after sowing (DAS), and 22% at 49 DAS. The decline of immobilized N at 42 and 49 DAS for the 2.5 g stover was ascribed to remineralization of N immobilized earlier. From the results of N uptake, the substitution value recovered was between 0.23 and 0.41 for S. sesban. Application of low quality organic materials (maize stover) in combination with high quality organic materials has shown initial immobilization of inorganic N that has been mineralized by the high quality organic materials and is slowly remineralized later.
Long-term impact of a gliricidia-maize intercropping system on carbon sequestration in southern Malawi
Makumba, W. ; Akinnifesi, F.K. ; Janssen, B. ; Oenema, O. - \ 2007
Agriculture, Ecosystems and Environment 118 (2007)39539. - ISSN 0167-8809 - p. 237 - 243.
soil properties - agroforestry systems - organic-matter - crop residue - central ohio - tillage - dynamics - nitrogen - yields - management
Tree/crop systems under agroforestry practice are capable of sequestering carbon (C) in the standing biomass and soil. Although studies have been conducted to understand soil organic C increases in some agroforestry technologies, little is known about C sequestered in simultaneous tree/crop intercropping systems. The main objective of this study was to determine the effect of agroforestry practice on C sequestration and CO2-C efflux in a gliricidia-maize intercropping system. The experiment was conducted at an experimental site located at the Makoka Agricultural Research Station, in Malawi. The studies involved two field plots, 7-year (MZ21) and 10-year (MZ12), two production systems (sole-maize and gliricidia-maize simultaneous intercropping systems). A 7-year-old grass fallow (Grass-F) was also included. Gliricidia prunings were incorporated at each time of tree pruning in the gliricidia-maize. The amount of organic C recycled varied from 0.8 to 4.8 Mg C ha¿1 in gliricidia-maize and from 0.4 to 1.0 Mg C ha¿1 in sole-maize. In sole-maize, net decreases of soil carbon of 6 Mg C ha¿1 at MZ12 and 7 Mg C ha¿1 at MZ21 in the topsoil (0¿20 cm) relative to the initial soil C were observed. After 10 years of continuous application of tree prunings C was sequestered in the topsoil (0¿20 cm) in gliricidia-maize was 1.6 times more than in sole-maize. A total of 123¿149 Mg C ha¿1 were sequestered in the soil (0¿200 cm depth), through root turnover and pruning application in the gliricidia-maize system. Carbon dioxide evolution varied from 10 to 28 kg ha¿1 day¿1 in sole-maize and 23 to 83 kg ha¿1 day¿1 in gliricidia-maize. We concluded that gliricidia-maize intercropping system could sequester more C in the soil than sole-maize.
The long-term effects of a gliricidia-maize intercropping system in Southern Malawi, on gliricidia and maize yields, and soil properties
Makumba, W.I.H. ; Janssen, B.H. ; Oenema, O. ; Akinnifesi, F.K. ; Mweta, D. ; Kwesiga, F.R. - \ 2006
Agriculture, Ecosystems and Environment 116 (2006)1-2. - ISSN 0167-8809 - p. 85 - 92.
defining competition vectors - alley cropping system - midwestern usa - dynamics - nitrogen - ultisol
A gliricidia¿maize (Gliricidia sepium (Jacq.)¿Zea mays L.) simultaneous intercropping agroforestry system has shown to be a suitable option for soil fertility improvement and yield increase in highly populated areas of sub Saharan Africa where landholding sizes are very small and inorganic fertilizer use is very low. An 11 year old field experiment, gliricidia¿maize simultaneous intercropping, with and without a small application of inorganic fertilizer was studied to increase our understanding of the long-term effects of continuous applications of gliricidia prunings on maize yield and soil chemical properties. The main objectives were to assess: (1) the yield of gliricidia prunings under intensive pruning management, (2) the effect of continuous applications of gliricidia prunings and fertilizer on maize yield and soil properties. During 11 years of intensive pruning, gliricidia trees maintained high levels of leafy biomass production (4¿5 Mg DM ha¿1). Application of gliricidia prunings increased maize yield three-fold over sole maize cropping without any soil amendments (3.8 and 1.1 Mg ha¿1, respectively). Maize yield declined with time under sole maize cropping system in both treatments with and without inorganic N fertilizer. Application of inorganic fertilizer (46 kg N ha¿1) in agroforestry systems increased maize yield by 29% (P = 0.002). Application of inorganic P did not significantly increase maize yield implying that the native P in the topsoil and P recycled through gliricidia prunings application was enough to support maize growth. The trees took up ¿native¿ soil nutrients (P, Ca, Mg and K) from the depth and pumped these to the surface soil. A net soil nutrient decrease in the gliricidia¿maize simultaneous intercropping system was observed due to increased nutrient export
Influence of time of application on the performance of Gliricidia prunings as a source of N for maize
Makumba, W.I.H. ; Janssen, B.H. ; Oenema, O. ; Akinnifesi, F.K. - \ 2006
Experimental Agriculture 42 (2006)1. - ISSN 0014-4797 - p. 51 - 63.
mineralization - seedlings - soil
Asynchrony between nitrogen (N) released by organic materials and N demand by the crop leads to low N use efficiency. Optimizing the time of application could increase the N recovery. A field experiment was designed to determine the effects of time of application of Gliricidia sepium prunings and of the addition of small doses of inorganic N fertilizer on N recovery and yield of maize. Six split applications of gliricidia prunings (in October, December and February) were compared. The prunings were incorporated into the soil while fresh. The application in October was done four weeks before planting the maize. Higher N uptake and maize yields were obtained when gliricidia prunings were applied in October than when applied in December and February. The corresponding substitution values were 0.66, 0.32 and 0.20. Split applications of prunings prolonged mineral N availability in the soil until March but did not increase N uptake and maize grain yield compared to a sole application in October. Combinations of gliricidia prunings and inorganic fertilizer increased N uptake and maize yield over prunings alone but the effect was only additive. We concluded that application of gliricidia prunings in October was more efficient than application in December and February
|Tree Root Architecture
Akinnifesi, F.K. ; Rowe, E.C. ; Livesley, S.J. ; Kwesiga, F.R. ; Vanlauwe, B. ; Alegre, J.C. - \ 2004
In: Below-ground Interactions in Tropical Agroecosystems: Concepts and Models with Multiple Plant Components Wallingford : CAB International - ISBN 9780851996738 - p. 61 - 81.