Response of Maize-Green Gram Intercropping to Manure and Mineral Fertilizers in Post Mined Soils

Abstract

Mining is an important economic activity globally that is associated with provision of raw materials, industrial growth, employment creation as well as degradation of natural ecosystems and agricultural land. A study was conducted at Base Titanium limited mining company to evaluate the response of maize-green intercrop to farmyard manure and mineral fertilizer in post mined soils.  Treatments were sole manure, sole inorganic fertilizer, manure + inorganic fertilizer and unfertilized (control) laid down in randomised complete block design (RCBD) and replicated three times.  Data collected included soil nutrients before and after cropping, maize and green grams growth and yield parameters. Obtained data was subjected to analysis of variance using genstat software and means separated using Fisher's LSD. The post mined soils were slightly acidic with optimal levels of Ca, Mg, Mn and Zn, Low levels of P,K, S, B,Cu, CEC, TN and organic matter. After two cropping seasons, S and TN was observed to increase in all treatments, while Ca, Mg, Mn, B and Zn decreased in all treatments. Combined manure and fertilizer application increased average maize plant height, stem circumference and LAI by 38%, 34%, 60% respectively and ears per plant, cob length, grains per cob, grain yield and dry matter weight by 57%, 13%, 47%, 31% and 35% respectively compared to unfertilized plants. Green grams growth and yield in the intercropping system was however not significant after either manure and/or fertilizer application. Although the findings showed that manures and fertilizers application improved nutrient availability in this post mined soils, further research is required to ascertain maize–green gram intercrop, optimal establishment time, spacing, fertilizer and manure rates that can provide optimal intercrop yield as well as soil regeneration.