Di-ammonium phosphate (DAP) and plant density improve grain yield, nodulation capacity, and profitability of peas (Pisum sativum L.) on ferralsols in eastern D.R. Congo

Abstract

Sustaining high crop yield and profitability on marginal soils, such as degraded ferralsols, calls for the use of adequate farming practices. In this study, we assessed for four cropping seasons the effect of di-ammonium phosphate (DAP) fertilizer application doses (100, 150, and 200 kg ha−1) and plant densities (100,000, 166,666, and 250,000 plants ha−1) on growth, yield, nodulation capacity, and profitability of two pea varieties (Adei and Rwanda) under degraded ferralsols in eastern Democratic Republic of Congo (DRC). Results showed that pea growth, yield, nodulation, and profitability were significantly affected by the DAP dose and the plant density. Application of 150 kg ha−1 of DAP improved pea yields from 730 to 1720 kg ha−1 and nodulation from 17 to 22 nodules per plant. The number of active nodules was positively correlated with total number of nodules, DAP doses, yield parameters, and plant height. High grain yield was recorded during the long rainy season (1400 kg ha−1) compared to the short one (930 kg ha−1). All DAP doses were profitable according to the agronomic efficiency (AE) and value–cost ratio (VCR) analyses. For improved and profitable pea production on degraded South-Kivu ferralsols, applying 150 kg ha−1 of DAP combined with low plant density are to be recommended and preferably in the long rainy season.

Optimization of plant density and fertilizer application to improve biofortified common bean (Phaseolus vulgaris L.) yield on Nitisols of South-Kivu, Eastern D.R. Congo

“…1 South-Kivu soil map and location of Kabare territory, eastern DR Congo. The soil classification was made based on the WRB classification [ 8 ]). …”

“…These low yields of common bean are due to many factors such as inadequate farmer practices, low soil fertility, lack of high yielding varieties, and high pressures of disease and insect pests [ 7 ]. Many scholars recommended different planting density and fertilizer use as a means for improving crop yield by smallholder farmers [ 1 , 8 ]. Thus, increasing plant density and using fertilizer could be promising practices to fill the yield gap in common bean cultivation.…”

“…Ferralsols and nitisols are the dominant soil groups in agricultural areas of eastern DR Congo [ 7 , 8 , 12 ]. They are acidic soils with low cation exchange capacity (CEC), low base saturation and high phosphorus fixation due to high concentrations of aluminum and iron oxides [ 13 ].…”

“…This situation is very limiting for the growth and development of crops such as common beans. These highly weathered soils are also characterized by low nutrient availability, including nitrogen, soil organic carbon and nutrients required for nitrogen-fixing bacteria to thrive and effectively fix nitrogen [ 8 , 17 ]. This can limit nitrogen availability for legume growth, which relies on starter nitrogen to promote symbiotic fixation.…”

Changes in Phenolic Profile and Total Phenol and Total Flavonoid Contents of Guadua angustifolia Kunth Plants under Organic and Conventional Fertilization

“…The use of conventional fertilizers, like diammonium phosphate (DAP), improves the nitrogen and phosphorus content in the soil, increasing the chlorophyll content and plant yield. , Also, organic fertilizers have a beneficial impact on the soil microbiome, since they may prime microbial activities and act as a biologically active agent and/or enhance synergistic interactions within the soil microbiome in enhancing plant biomass . In addition, biological inoculants improve soil fertility and crop production, − by enhancing beneficial elements like nitrogen, phosphorus, potassium, vitamins, and proteins. − …”