Development of Slow-Release Fertilizer from Animal Origin Wastes: Sustainable Organic Agriculural Perspective

Abstract

Improved crop quality and quantity is the main target of soil fertilization in conventional agriculture. However, in organic agriculture, adding nutrients to the soil is the threshold replenishment of nutrients lost through every crop. Mineral fertilizers provide essential macro and microelements to plants for their active growth and development. Unfortunately, these kinds of fertilizers easily run off from plant vicinity because of frequent watering and rain. This leads to the recurrent application of fertilizers, which causes severe environmental problems. To resolve these issues many researchers developed different slow-release fertilizers, which can provide nutrients to plants for an extended period. However, slow-release fertilizers are much more expensive than normal mineral fertilizers. The present work attempts to develop new slow-release fertilizer using mariculture waste mussel shell and cow urine. Significant macronutrient adsorption was observed in the shell saturation experiment and the leaching experiment proves that shell powder after nutrient impregnation with urine had a slow nutrient-releasing capacity. The formation of struvite crystals is another highlight of this study, which provides a long-term nutrient supply in the soil. BET analysis confirms the nutrient scrubbing and releasing ability of shell powder. Independently cow urine and mussels shells are used in agriculture for different purposes. Mussel shells are regularly used to reduce soil acidity and cow urine is applied to plants as a cheap nitrogen supplement in a diluted manner. However, cow urine components quickly run off from the plant root proximity. Nutrient impregnated shell powder has both characters of mussel shell powder and cow urine and it is truly formed from animal origin waste products. Because of no usage of synthetic chemicals, new slow-release fertilizer couldn’t make any environmental problems.