Evaluation of Biological Soil Fertility Management Practices for Corn Production in Oxisols

Abstract

Field trials on the management of soil biological fertility with aim to increasing corn production were conducted in a savannah region of the DR-Congo. Three organic matters including fresh biomass of Entada abyssinica, Tithonia diversifolia, Stylosanthes gracilis and a mineral combination of nitrogen and phosphorus (NP) (115-63-0) along with a control (without fertilization) were evaluated for corn crop growth and production. The field trial was a completely randomized design with four replicates. Plant height, basal stem diameter, and yield components were assessed. Irrespective of fertilization treatments and variety, maize showed a similar growth up to 20 days after sowing (DAS), and then two distinct trends were observed. At 60 DAS, plant height and basal diameter were significantly bigger in plots treated with NP, T. diversifolia and E. abyssinica compared to S. gracilis treatment and control (NoF). This pattern was also confirmed with agronomic traits such as cob length, number of kernel per cob, and net grain yield. The local variety was the least productive under any treatment. In general, the response of corn crop to organic and inorganic fertilization showed that the mineral combination (NP) increased the most grain yield and other yield components compared to unfertilized trial, followed by T. divessifolia and E. abyssinica. NP and T. diversifolia treatments increased significantly and equally soil potassium content compared to control and other treatments. Application of T. diversifolia appears a more cost effective approach for small farmers to improving fertility of the oxisol prevailing in Central Africa compared to mineral fertilizers.

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

“…Based on the data from the present study, organic fertilizer application can be recommended because of its reasonable cost compared to the inorganic fertilizer. The results are consistent with previous soil chemical analyses that revealed that site 2 (Mpiana) is more fertile than site 1 (INERA) [12][13]. This explained the relative increase in the GI observed at this site 2.…”

“…In the present study, expected and obtained yield for soybean and maize under MF, TDN and EAB application were similar. Based on previous reports, the inorganic fertilizer may have provided a large part of the nutrients and the organic fertilizer may have increased soil organic matter status, structure, and buffering capacity in the fertilized sites [12,35]. In general, the organic matter also improves phosphorus (P) availability through reduction of the P sorption capacities of soil and supply of the P release during their decomposition [36][37].…”

“…The amount of nitrogen was below detectable limits at site 1 (INERA) and varied between 47 to 115 mg kg -1 at site 2 (Mpiana). Details of soil chemistry for the targeted sites are described in Muyayabantu et al [11,12,13].…”

“…Maize based cropping systems are very popular in the tropics. In general, small farmers in the DR-Congo practice maize/legumes association (especially maize-soybean intercropping) without using any fertilizer [10,11,12,13]. In intercropping system, the cereal species are usually taller; they grow faster than the legume species.…”

Responses of Maize and Tomato Crops to Fertilization with Three Agroforestry Litter Species (Annona senegalensis, Terminalia macroptera and Parkia biglobosa)

“…The growth variables were observed two months after sowing for the two crops, while yield parameters were evaluated at harvest. For each parameter, the measurements were carried out on ten plants chosen randomly from an experimental plot, for a total of 30 plants per treatment [32]. The parameters taken into account for the cultivation of maize are: the crown diameter, the plant height, the number of rows per cob, the biomass, the weight of 100 grams, the cob weight with or without husks.…”