Microwave-Assisted Synthesis of a Semi-interpenetrating Polymer Network Slow-Release Nitrogen Fertilizer with Water Absorbency from Cotton Stalks

Abstract

A semi-interpenetrating polymer network (semi-IPN) slow-release nitrogen fertilizer with water absorbency was synthesized via microwave irradiation. Urea was incorporated as the nitrogen source into a cotton stalk-g-poly(acrylic acid)/ bentonite (CS-g-PAA/bent) network and linear polyvinylpyrrolidone (PVP). A reaction mechanism for synthesis of CS-g-PAA/ bent/PVP/urea was proposed. Variables influencing water absorbency, such as microwave power, irradiation time, and contents of CS, PVP, and bent were evaluated and optimized. The sample prepared under optimized conditions had a water absorbency of 1018.4 g/g in distilled water and 71.3 g/g in 0.9 wt % NaCl solution. The structure and properties of samples were characterized through various analysis technologies. Swelling measurements and water-retention study indicated that the sample possessed excellent water absorbency in different environments and enhanced the water-retention capacity of soil by introduction of bent and formation of a semi-IPN structure. Investigation of leaching behavior indicated that the sample has the potential to carry the necessary N. The results indicated that about 60% of nutrients were released after 30 days based on anomalous transport, and the sample improved the seed germination rate and promoted cotton growth. Thus, microwave irradiation is a possible method to produce slow-release fertilizers that could be widely applicable in agriculture and horticulture.

Evaluation of almond young trees growth and nutritional status under different slow-release compound fertilizer types and doses at Nubaria region

“…The results indicated that Matador and Nitrophoska have good slow-release compound fertilizers which provided an efficient way of supplying trees with essential elements to growth especially under sandy soil conditions such as Nubaria region which is characterized with poor fertility, low water holding capacity, and easily leaching of nutrients from the soil as well as to prevent environmental pollution compared with fast-release mineral fertilizer and cost-saving, thus can efficiently improve the utilization efficiency of fertilizers. These results are in accordance with those obtained by Wen et al (2016); slow-release fertilizers may be a promising approach to alleviate such problems and improve nutrient utilization efficiency at the same time directly through its design at form releases the nutrients gradually at the rate in accordance with the nutrient requirement of the plants, which is conducive to the reduction of nutrient loss (Teodorescu et al, 2009). Also they gave the highest values of residual elements in soil due to their low activity index, compared with the fastrelease mineral fertilizer which gave the lowest values of available elements left in the soil (Mikkelesen et al, 1994).…”

Construction and water absorption capacity of a 3D network‐structure starch‐g‐poly(sodium acrylate)/PVP Semi‐Interpenetrating‐Network superabsorbent resin

“…The resin showed good water absorbency of 198.5 g/g in distilled water and 26.3 g/g in 0.9 wt% NaCl solution. Similarly, a semi‐IPN polymer network (CS‐g‐PAA/bent/PVP/urea) for slow‐release nitrogen fertilizer reported by Wen et al also presented outstanding slow‐release performances and the excellent water absorbency of 1018.4 g/g in distilled water and 71.3 g/g in 0.9 wt% NaCl solution . Obviously, the technology brings a convenient method for preparing multi‐component polymer materials and a flexible strategy to improve the properties of natural polymer‐based resins.…”

Preparation of a Slow Release Biofertilizer From a Polymeric Urea-Formaldehyde Matrix (PUFM)

“…The industry of fertilizers must increase the efficiency of its products, improving or developing new types of fertilizers to avoid or reduce environmental pollution. It is considered that an ideal fertilizer should have at least three characteristics: a high percentage of recovery and production; a minimum negative impact on the environment and with a single application of the product should be enough to cover the nutritional requirements during the entire culture period [9][10][11][12][13][14]. According to these characteristics, Slow Release Fertilizers (SRF) have a relevance nowadays.…”

“…The obtention of SRF constitutes a technology that meets the three characteristics of an ideal fertilizer. The use of SRF helps preventing soil degradation, can be used to reduce the amount of fertilizer that is applied and make the nutrients available for longer periods of time after application, since they avoid losses due to leaching and volatilization of the fertilizer [3,[9][10][11][12][13][14][15].…”