Biodegradable oil-based polymeric coatings on urea fertilizer: N release kinetic transformations of urea in soil

Abstract

Polymer coatings are used to control the rate of release of plant available nutrients from fertilizers as well as to reduce nutrient losses such as ammonia (NH 3) volatilization. Although the literature presents several examples of materials used to coat urea, little is known about nitrogen (N) release properties such as the mechanism involved and phenomena (e.g., pore opening) in the polymer coating. Thus, this study investigated urea release from polyurethane (PU) derived from two renewable raw materials (castor oil and soybean oil), to explain how the oil structure and coating microstructure influence release and urea-N dynamics in soil. The results demonstrated that the profile of urea release and the urea-N mineralization in the soil could be controlled by altering the thickness of the coating on the urea granules. Coating by eco-friendly polymer was efficient in controlling urea release in soil to reduce volatilization of ammonia and increase the availability of N in the soil.

Different Zn loading in Urea–Formaldehyde influences the N controlled release by structure modification

“…The results confirm the low availability of N-NH 4 + species after 42 days of urea incubation in soil. This low efficiency is attributed to the high NH 3 volatility, which in this study was 32% by the end of the experiment 36 – 38 . As previously discussed, although urea provides high availability of N-NH 4 + 14 days after incubation, the available N for plant absorption considerably reduces after 28 days (Fig.…”

Filler-Modified Castor Oil-Based Polyurethane Foam for the Removal of Aqueous Heavy Metals Detected Using Laser-Induced Breakdown Spectroscopy (LIBS) Technique

“…Led by the rise of environmental concern, a new trend in PU research has been shifted to the use of bio-polyol resources. Lignin, starch, cellulose, chitosan, and vegetable oils (including castor oil) are some examples of many bio-polyols that have been used by researchers in PU synthesis for multiple applications in either pharmacy, building construction, packaging, agriculture, or other fields [16][17][18][19][20][21].…”

“…This material can appear in an open or closed cell structure with a wide range of rigidity (rigid, semirigid, and flexible foam) [19]. Hence, PUF has been noticeable for its high applicability as a thermal insulator [16], adhesive [17], and fertilizer release controller [21], and many others. In this research, however, we will employ PUF's applicability in heavy metal removal by incorporating activated carbon, bentonite, and zeolite as modifying fillers.…”

Different Zn Loading in Urea-Formaldehyde Influences the N Controlled Release by Structure Modification

“…The results con rm the low availability of N-NH 4 + species after 42 days of urea incubation in soil. This low e ciency is attributed to the high NH 3 volatility, which in this study was 32 % by the end of the experiment [37][38][39] . As previously discussed, although urea provides high availability of N-NH 4 + 14 days after incubation, the available N for plant absorption considerably reduces after 28 days (Fig.…”