Productivity efficiency of two animal manure sources on intercropped maize-groundnut in Ishiagu, Ebonyi State in the derived savanna, Nigeria
Two animal manure sources (swine and sheep/goat manures) each at 5 Mt·ha-1, were applied in mono- and intercropped maize (Zea mays L.) and groundnut (Arachis hypogea L.) to assess their effects on growth, yield and productivity of the systems. A general control (no manure treatment of the component crops was established) for productivity assessment. The trial was conducted at the Federal College of Agriculture, Ishiagu, in the derived savanna plains, Ishiagu, Nigeria in 2012 and 2013 mid-cropping seasons. The experiment was laid out in a randomized complete block design with three replications. Maize and groundnut were planted in monocrop and intercrop without manure, and with swine manure or goat/sheep manure. Some of the growth and yield data collected from the component crops were plant height, number of leaves·plant-1, stem girth, cob length, number of seeds·m-2, weight of seeds·m-2, number of pods·m-2 and grain yield. All the data were statistically analysed and means compared with least significant difference at p<0.05 level of significance. The combined analysis indicated that animal manure sources significantly (P<0.05) increased growth and yield of the crops in the systems. The economic and biological productivity indices indicated that the application of sheep/goat manure in the mixture exhibited greater intercrop advantage. Hence, the application of sheep/goat manure gave higher gross monetary return, % land saved and total land equivalent ratio, which was higher by 13.76%, 7.50% and 4.79 %, respectively relative to swine manure application. Therefore, sheep/goat manure application should be encouraged in maize-groundnut intercrop.