Title “Organic Fertilizers” in Vietnam’s Markets: Nutrient Composition and Efficacy of Their Application

Abstract

Organic fertilizers have recently been gaining popularity; however, their governance is not completely assessed in developing countries. This study investigated the nutrient composition of so-called organic fertilizers in Vietnam's markets and issues related to their production, and evaluated their potential to contaminate the groundwater. We analyzed the physicochemical properties of 12 domestic and four imported products of the fertilizers, and conducted a cultivation experiment in sandy soil with the fertilizer applied at a rate of 200 mg N kg −1 soil using an automatic watering apparatus in a greenhouse. We further studied the production of an "organic fertilizer" from coffee by-products. The nutrient content greatly varied among domestic products, whereas they were quite similar among imported products. The product packaging of the collected samples lacked information regarding raw materials. Two thirds of the domestic products contained over 30% of the total N in the inorganic form, implying that the N content dramatically increased in the fertilizers rather than in their supposed raw materials. The stages involved in the production were composting, the addition of extra soil as a bulking agent, and the mixing-in of chemical substances to increase the nutrient content before packing. The remarkably high ratio of inorganic N to total N was attributed to excessive N leaching from soil by the application of domestic fertilizers. These results suggested the need for quality criteria guidelines for organic fertilizers in Vietnam that underline not only nutrient levels, but also the control of raw materials and production process of compost, because they are closely related to nutrient uptake and the leaching loss of nutrients.

Perceptions, Risk Attitude and Organic Fertilizer Investment: Evidence from Rice and Banana Farmers in Guangxi, China

“…Consequently, the Chinese government has recently exerted increasing efforts to reduce chemical fertilizer overuse and aim to reach zero growth in chemical fertilizer and pesticides use by 2020, which specifies incentive subsidies and tax exemption to organic fertilizers as well as formula fertilization with soil testing [10,11]. It is widely recognized that organic fertilizer can significantly improve soil quality and nutrition, farm productivity, and avoid adverse environmental and health impacts from agricultural chemical use and thus help achieve sustainable agricultural development [2,[12][13][14][15][16][17]. However, the adoption rate of organic fertilizer is still low compared to the increasing usage of chemical fertilizer because many farmers fear the loss of crop output and the odor of organic fertilizer [18,19].…”

Organic Fertilizer Production and Application in Vietnam

“…According Vietnam General Statistic Office in 2015, Vietnam produced 45.22 million tons of rice, 5.28 million tons of maize, 10.67 million tons of cassava, 1.445 million tons of coffee and 18.320 million tons of sugar cane. Based on crop biomass and product, (Trinh) [15] calculated the agricultural waste approximate 76 million tons including 45.22 million tons of rice straw, 8.73 million tons of rice husk, 4.04 million tons of sugarcane bagasse (SCB), 6.33 million tons of maize byproducts, 1 million tons of coffee shell and 10 million tons of vegetable by-products [15]. Agricultural waste contained not only the carbohydrate composition and plant essential nutrition like NPK and microelement [14] ( Table 2).…”

“…Vietnam exported every year more than 7 million tons of seafood products and made more than 5 million tons of seafood by-products that can be used as raw material for organic fertilizer production [15]. Seafood processing by product is protein, lipid and micro element ( Table 4).…”

Assessment and Governance of Sustainable Soil Management

“…A third level of assessment is provided by Quynh and Kazuto [45]. The authors assess the impact of specific organic fertilizers on nutrient use efficiency and water quality.…”