Influence of Tillage Practice and Cropping System on Growth Attributes and Grain Yield of Maize [Zea mays L.] in the Forest Agro-ecological Zone of Ghana

Tillage is one of the most important practices in agricultural production due to its influence on the physical, chemical, and biological properties of the soil environment. Field experiments were conducted to find out the effects of tillage practice and cropping system on the growth attributes and grain yield of maize within the Forest agro-ecological zone of Ghana from 2011 to 2014. The experimental design was a randomized complete block, arranged in a split plot with four replications. Minimum tillage [MT] and Full tillage [FT] were the main treatments. Maize intercropped with mucuna [Maize/M]; maize intercropped with pigeon pea [Maize/Pp]; maize intercropped with cowpea [Maize/C]; sole maize with recommended rate of mineral fertilizer [Maize/F] and sole maize with minimum mineral fertilizer application [Maize] were the subplot treatments. In the first year all the treatments received 30-20-20 kg N-P2O5-K2Oha-1 [F1] except Maize/F which received 60-40-40 kg N-P2O5-K2Oha-1 [F2]. Interaction between tillage and cropping system showed a similar pattern of plant growth during the first and second years. However, grain yield for the second year was at least 50% less than the first year even though plant growth and grain yield were similar for most of the interactions. In the third year grain yield, Maize/Pp + F1 [3.34 t/ha] under MT produced significantly higher grain yield than most other treatment combinations except Maize/M + F1 [3.12 tha-1] and Maize/Pp + F1 [3.31 tha-1] both under FT. In the fourth year grain yield for Maize/Pp + F1 [3.41 tha-1] under MT and Maize/Pp + F1 [3.45 tha-1] under FT were similar but significantly higher than all the other treatment combinations. All other combinations recorded grain yields below 2.50 tha-1. From this study, Maize intercropped with Pigeon pea showed the highest potential under both minimum and full tillage practices. For increased and sustainable maize production within the forest agro-ecology in Ghana, this system is therefore recommended for maize farmers, particularly the poorly resourced farmers.