Potentials of cover crops for sustainable short fallow replacement in low-input systems of maize production in the humid tropics.

摘要

A field experiment was conducted in Umudike, Nigeria, from 1999 to 2003 to evaluate the growth of 11 cover crops incorporated into the soil as green manures after 3 years of fallow, and investigate their effects on the performance of 2 maize cultivars (FARZ 23 and TZBR Eldana 2C3). The green manures were Chamaecrista rotundifolia, Pueraria phaseoloides, Aeschynomene histrix, Centrosema pascuorum, Centrosema brasilianum, Stylosanthes capitata, Mucuna pruriens, Mucuna deeringiana, Mucuna veracruz, Crotalaria ochroleuca and Lablab purpureus. M. deeringiana and M. veracruz showed superior growth (in terms of biomass production) at 3 months after planting. However, Aeschynomene histrix produced the greatest biomass at 3 years after planting. M. pruriens, Crotalaria ochroleuca and L. purpureus did not persist due to their inability to compete with the native vegetation. A. histrix fallow resulted in a greater maize dry matter yield than Centrosema pascuorum, Centrosema brasilianum, L. purpureus and grass cover. The average grain yield ranged from 1260.4 (Mucuna pruriens) to 2399.4 kg/ha (A. histrix) fallow in 2002, and from 640.7 (L. purpureus) to 1428.2 kg/ha (Stylosanthes capitata fallow) in 2003. In 2002, grain yields obtained with A. histrix improved fallow were similar to those obtained with Chamaecrista rotundifolia, Centrosema brasilianum and NPK fertilizer treatment, but lower than those obtained with other cover crop fallows. Generally, the cultivar and cultivar x cover crop interaction had no significant effects on maize growth and yield..