Efficacy Evaluation of Organic Fertilizers on Growth, Yield and Quality Parameters of French Beans, Maize and Kale in Different Counties of Kenya

Sustainable agriculture is an important global issue. Organic fertilizer application improves crop growth by supplying plant nutrients, including micronutrients, as well as improving the physical, chemical, and biological properties of the soil, thereby providing a better environment for root development by improving the soil structure. It has been widely reported that continuous applications of inorganic fertilizers alone resulted in deterioration of soil health in terms of physical, chemical, and biological properties of the soil. Understanding the nutrient variability and release pattern of organic fertilizers is crucial to supply plants with sufficient nutrients to achieve optimum productivity, while also rebuilding soil fertility and ensuring protection of environmental and natural resources. This study was conducted to determine the efficacy of Fertiplus on growth, quality and yield in Kale, Maize and French Beans in Kenya. The trial plots were 3 m×3 m arranged in a randomized complete block design and replicated 4 times. The treatments consisted Fertiplus 4-3-3 alone; Fertiplus 4-3-3+100% recommended fertilizer practice; Fertiplus 4-3-3+50% recommended fertilizer practice; Fertiplus 4-3-3+75% recommended fertilizer practice; Reference product (Permeate); recommended fertilizer practice (Conventional) and the absolute control. Application of Fertiplus plus 50% of the recommended fertilizer practice led to the highest number of pods per plant (18) and application with 75% of the recommended fertilizer practice showed a peak harvest of fresh pods with 374.3 g per plant. In an area of 1 m2, application of Fertiplus and 50% recommended fertilizer practice had 6.7 kilograms of kale with a maximum of 14 mature leave per plant in a span of 20 days. In maize, the Fertiplus and 50% recommended fertilizer treatment showed the highest cob weight per plant (480 g) and an average grain yield of 396.7 g per plant compared to the doubled level (100%) of the recommended fertilizer practice that had 401 g per plant. From the study, it was observed that the highest yield of the three study crops were under the integrated treatments of the organic fertilizer and half the rate of synthetic fertilizer program.