Assessing the Effects of Integrated Soil Fertility Management on Biological Efficiency and Economic Advantages of Intercropped Maize (Zea Mays L.) and Soybean (Glycine Max L.) in DR Congo
G. M. Muyayabantu
University of Kinshasa, B.P 117 Kinshasa 11, RD-Congo
B. D. Kadiata
University of Kinshasa, B.P 117 Kinshasa 11, RD-Congo
K. K. Nkongolo *
Department of Biological Sciences, Laurentian University, Sudbury, Ontario, Canada, P3E 3C6
*Author to whom correspondence should be addressed.
Abstract
Interactions among species play an important role in determining the structure and the dynamics of plant communities. The main objectives of the study were (i) to assess and compare different competition indices and their relationship with yield component under different inorganic and organic fertilizers regimes; and (ii), to identify nutrient management regimes options that lead to high yields and incomes in a maize-soybean intercropping system. Effects of integrated soil practices management on crop competition, yields components and economics advantage in maize-soybean intercropping system in a savannah region of the DR-Congo were investigated. Field trials were conducted at two sites in a randomized complete block design with six treatments replicated four times. Grain yield and yield components increased under integrated soil fertility management (ISFM) (inorganic or mineral and organic fertilization combined) than other treatments at the two sites of the study. Organic biomass application resulted in similar grain yield production than the inorganic (mineral) fertilizer application. The required land decreased when soil was fertilized compared to the control. Land equivalent coefficient (LEC) values ranged from 0.50 to 0.79. Soybean intercropped with maize resulted in an area-time equivalency ratio (ATER) higher than 1 for all the treatments confirming the intrinsic advantage of intercropping over sole crops. Among all the treatments, integrated nutrient management (ISFM) resulted in higher yields and monetary advantage index (MAI) values for maize/soybean mixture compared to other treatments. The highest MAI of 343891 was generated by the Tithonia (organic) – inorganic applications
Keywords: Cropping system, land equivalent ratio, land equivalent coefficient, area-time equivalency ratio, monetary advantage index, plant competition, maize and soybean yields, DR-Congo