Preparation of an Environmental Friendly Slow Release Nitrogen Fertilizer

Abstract

An environmental friendly slow-release urea fertilizer with double films (SUFDF) was prepared by using dialdehyde starch urea resin (DASU) as inner coating and polylactic acid (PLA) as outer materials. The structural, chemical characteristics and morphology of the SUFDF were characterized by FTIR, element analysis and SEM. Its efficiency in slowing the nitrogen release was examined via soil leaching and pot experiments. The experimental results indicated that the introduction of hydrophobic PLA and DASU reduced the swell ability of the fertilizer, which made it can provide nitrogen persistently at the early farming. After the urea dissolved, the DASU in the fertilizer would continue to release nitrogen due to its good slow-release property. So this fertilizer would have potential applications in modern agriculture and horticulture.

Characterization of p(AA‐co‐AM)/bent/urea and its swelling and slow release behavior in a simulative soil environment

“…The peak at 3259 cm −1 was due to OH vibration of absorbed water, 2802 cm −1 was identified as CH of formaldehyde in the urea . The peak that appeared at 1681 cm −1 was attributed to CO groups stretching, 1623 and 1465 cm −1 were corresponded to N‐H bending vibration and CN stretching vibration, 557 cm −1 was related to NCON bending vibration, and these peaks still existed in p(AA‐co‐AM)/Urea and p(AA‐co‐AM)/Bent/Urea, which indicated the involvement of urea in the samples and the chemical structure of the urea is stable. In FTIR spectra of p(AA‐co‐AM)/Bent, p(AA‐co‐AM)/Urea, and p(AA‐co‐AM)/Bent/Urea, the bands at 1673, 1681, and 1673 cm −1 were related to the overlapped stretching vibration of the CO groups of AA and AM as well as the NH bending .…”

Nitrogen fixation and chelating property of wheat ammonium sulfite pulping spent liquor

“…Therefore to find a way to utilize such liquor is the prime requirement for the success of pulping process. Agricultural utilization of chemically modified sulfite pulping spent liquor can be the avaiable way to produce slow nitrogen releasing fertilizer, phosphate fertilizer activator, nitrogen fertilizer synergist, and seed dressing (Li 2006;Zhu et al 2001;Fan et al 1995;Liu et al 1998;Meier et al 1994). The main component of the spent liquor is lignosulfonate, which is a high-molecular network with high C/N ratio (~250) as well as active groups.…”