Composting Cow Dung Enriched with Vivianite (Phosphocompost) for Agricultural Use in the Balaza Lawane Locality (Far North, Cameroon)

Abstract

Aims: Soils in the Far North of Cameroon are deficient in organic matter and available phosphorus, making it difficult to intensify agricultural production. This affects the yield of several crops. With this in mind, a study has been carried out to produce cow dung compost enriched with vivianite, to improve soil quality in terms of organic matter and available phosphorus, and boost agricultural production. Study Design: A study was carried out to produce cow dung compost enriched with rock phosphate (Vivianite). Place and Duration of Study: Balaza Lawane in Far North Region of Cameroon. The sowing was done on January 15, 2021 until 20 april 2021. Methodology: To this end, we produced 3 organic amendments based on cow dung (a compost and two phospho-composts containing 10 and 20% of vivianite, respectively). Monitoring and chemical characterization of each of the three was carried out. A seed germination test was also carried out, on petri dishes in a completely randomized block design repeated three times. Results: Physico-chemical analyses reveal that the soil at the Balaza Lawane site has a Sandy clay loam granulometry and an acid pH (6.8); it is low in organic matter and available phosphorus. The monitoring of the amendments showed that the temperature, the pH, and even the moisture content of the amendments changed in the same way over time. The application of vivianite powder improved the nitrogen, potassium, and phosphorus content of the phosphocomposts compared to the compost. Phytotoxicity tests showed that our various amendments had no phytotoxic effects. The 20 and 10% phosphocomposts showed higher germination index than the other treatments (157.33±16.32% and 157.01±15.32% respectively). An analysis of variance revealed a significant difference (p < 0.05) threshold. Conclusion: Compost enriched with 20% vivianite produced more available phosphorus, and showed no phytotoxicity. This phosphocompost is proving to be the most effective crop amendment on Balaza Lawane soil.