Enrichment of Organic Manures and Their Utilization in Vegetable Crops

Agriculture intensification through indiscriminate and irrational use of chemical fertilizers and pesticides has resulted in reduction of crop productivity, lowered fertilizer use efficiency, accelerated environmental degradation and soil heath thus posing serious threat to the sustainability of agriculture, ecological balance and human health. However, people are gradually realizing the emerging danger and showing interest in sustainable crop production practices such increased use of organic manures to revitalize and restore soil fertility and reviving the microbial activity of the soil. Traditionally farmyard manure, animal wastes, compost, vermicompost are used as source of organic fertilizers for improving soil fertility and crop productivity. However, low nutrient content, bulkiness, handling difficulties and labour intensive application prevent the growers for larger use of these traditional organic manures. Gradually there is a decline in microbial activity of these organic manures which in turn leads to depletion of enzymatic activity and composition of nutrient. Manure enrichment increases the nutrient content, microbial population, enzyme activity and increase the fertility status of the soil. Enrichment of manures and composts is done by incorporation of mineral additives (rock phosphate, zinc salt etc.), bio-fertilizers (nitrogen fixing, phosphorus and potassium solubilising bacteria etc.) and bio-inoculations (Trichoderma, Pseudomonas etc.) have lot of benefits on crops in terms of higher yield, better quality, increased disease and pest resistance, availability of essential nutrients and increased soil microbial population and activity. Regular use of higher amount of enriched organic manures will not only reduce the amount of organic manure requirements, but will also increase the use efficiency of the applied manures. Preparation and application of enriched organic manures should be promoted to more number of vegetable growers for organic cultivation as well as for traditional crop cultivation. The present review work on enrichment of organic manure was aimed to explore the possibility of preparation and utilization of enriched organic manures on vegetable crop growth, yield and soil health. The different enrichment method and their utilization will motivate the farming community to adopt enrichment of available organic manures which in turn reduce soil pollution and environmental degradation from fossil fuels.