Nitrogen release dynamics and transformation of slow release fertiliser products and their effects on tea yield and quality

2008 ◽  
Vol 88 (5) ◽  
pp. 839-846 ◽  
Author(s):  
Wen-Yan Han ◽  
Li-Feng Ma ◽  
Yuan-Zhi Shi ◽  
Jian-Yun Ruan ◽  
Sarah J Kemmitt
2020 ◽  
Vol 9 (1) ◽  
pp. 139-152 ◽  
Author(s):  
Xiao Zhang ◽  
Yanlu Liu ◽  
Panfang Lu ◽  
Min Zhang

AbstractA novel hydrogel slow-release nitrogen fertilizer based on sawdust with water absorbency was prepared using grafting copolymerization. Urea was incorporated as nitrogen source in a hydrogel fertilizer. Potassium persulfate (KPS) and N,N᾽-methylenebis acrylamide (MBA) were used as the initiator and cross-linker, respectively. The structure and properties of the samples were characterized by XPS, EDS, SEM, XRD and FTIR. The effects of various salt solutions, ionic strength and pH on swelling behavior were discussed. The results showed that the largest water absorbency of the sample reached 210 g/g in distilled water. In addition, the sample had the good nitrogen release property. Thus, the novel environmentally friendly hydrogel fertilizer may be widely applied to agricultural and horticultural fields.


Author(s):  
YC Danarto ◽  
Anggita Nugrahey ◽  
Sela Murni Noviani

<p>During this time, the use of urea is not efficient, because about 40-70% of nitrogen in the fertilizer is not absorbed by plants. In order to increase the effectivity of nitrogen release in urea fertilizer, it needs to be coated with modified chitosan as slow releasing agent to form a hydrogel material by forming a cross linking with glutaraldehyde cross-linker.The aims of this research is to study the mechanism and the appropriate kinetic model of nitrogen release in slow releasing fertilizer of modified chitosan. This research was conducted by analyzing the ability of bio-hydrogel by calculating the percentage of swelling ratio and water retention of hydrogel and the nitrogen release in slow releasing fertilizer both in the soil and water. The experiments were conducted by varying the amount of urea used which  30 gram, 40 gram, 50 gram, 60 gram and 70 gram of urea fertilizer. The The release profile is then plotted on several models of diffusion kinetic such as zero order, first order, higuchi and korsmeyer peppas. The appropriate model of diffusion kinetic is chosen by the largest correction factor (R2).The results showed that nitrogen release of the slow releasing fertilizer in the soil with 50% urea content  and  the  water  followed  korsmeyer  peppas  model  with  fickian  mechanism. Nitrogen release in the soil with urea content of 30%, 40%, 60%, and 70% followed the korsmeyer peppas model with nonfickian mechanism.</p>


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1549
Author(s):  
Bruno Maia Abdo Rahmen Cassim ◽  
Antonio Pedro Martins Machado ◽  
Daniel Fortune ◽  
Fernando Rodrigues Moreira ◽  
Éder Júnior De Oliveira Zampar ◽  
...  

The objective of the study was to evaluate the effect of foliar application of urea and urea-formaldehyde, triazone-based fertilizers on soybean and corn crops. Four experiments were carried out, two on soybeans, one on first season corn, and the other on second season corn. The experiments were conducted using a randomized block design, with 5 treatments studied: T1—control without application of foliar nitrogen (N); T2—foliar application of conventional urea solution and three treatments with Hexion foliar fertilizers based on urea-formaldehyde and triazone (N-Hexion®), with varying levels of N and slow-release components; T3—Hexion 1; T4—Hexion 2; and T5—Hexion 3. The foliar application of conventional urea showed no statistically significant difference in relation to the control for the yield components and grain yield for the soybean crops in seasons 2018–2019 and 2019–2020. Urea-formaldehyde/triazone treatments showed a significant increase in yield for soybeans in the 2018–2019 season compared to the control and to conventional urea. Nitrogen fertilizers with high percentages of slow-release compounds promote nitrogen release more slowly, which led to no significant increase in yield for Hexion 1. No statistical differences were observed in the corn yield for the first and second crop.


2018 ◽  
Vol 10 (8) ◽  
pp. 2740 ◽  
Author(s):  
Lu Chen ◽  
Qincheng Chen ◽  
Pinhua Rao ◽  
Lili Yan ◽  
Alghashm Shakib ◽  
...  

This study aimed to develop and optimize a novel biochar-based fertilizer composed of rice husk biochar and urea–hydrogen peroxide (UHP), which can simultaneously slowly release nitrogen and immobilize cadmium (Cd). Response surface methodology (RSM) was adopted to optimize the fertilizer formulation with the lowest nitrogen release rate. Under the optimized conditions, the cumulative nitrogen release rate of the biochar-based fertilizer was 17.63%, which was significantly lower than that of ordinary fertilizer. Elementary analysis, scanning electron microscopy (SEM) images, and Fourier transform infrared (FTIR) spectroscopy proved that UHP attached to the porous structures of the biochar. The adsorption test showed that the adsorption of Cd onto biochar-based fertilizer quickly reached equilibrium with an equilibrium adsorbing quantity (Qe) of 6.3279 mg·g−1 with an initial concentration of 10 mg·L−1. Compared to original biochar, the Cd immobilization ability of biochar-based fertilizer was significantly better. The adsorption of Cd on biochar-based fertilizer is mainly based on a monolayer adsorption behavior. Finally, improved crop growth was demonstrated by pot experiments, which showed a significant increase in the biomass of cabbage. The concept and findings presented in this study may be used as references in developing a novel biochar-based fertilizer for simultaneously enhancing crop yield and reducing environmental risk.


2014 ◽  
Vol 1015 ◽  
pp. 346-349 ◽  
Author(s):  
Jing Li ◽  
Yu Sen Hu ◽  
Lu Mei Pu ◽  
Guang Sheng Guo ◽  
Hong Yan Niu

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.


2013 ◽  
Vol 594-595 ◽  
pp. 798-802
Author(s):  
Zahid Majeed ◽  
Nur Kamila Ramli ◽  
Nurlidia Binti Mansor ◽  
Zakaria Man

Plant based biopolymers are abundantly and easily available naturally biodegradable raw materials to prepare slow release nitrogen technologies. To test the lignin loading effect on biodegradability of the slow release fertilizer (SRF) and nitrogen release applications, a pot experiment under real soil conditions was conducted. Lignin at different loading percentages 5%, 10%, 15% and 20% were mixed with urea-modified tapioca starch acting as slow release fertilizer (SRF). Increasing the percentage of lignin to starch reduced the weight loss with improved nitrogen slow release properties in wet soil. Soil microbial biomass was negatively correlated with increase of lignin percentages. Lignin is a low cost biopolymer and can be used to improve starch biodegradation and its slow release nitrogen properties.


2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Yi Zhong ◽  
Renyi Gui ◽  
Zhuangzhuang Qian ◽  
Shunyao Zhuang

Slow release fertilizers are designed to enhance crop yield and minimizing the loss of nitrogen (N) to environment. However, N release in leaching and loss in ammonia emission from bag controlled release fertilizers have not been previously evaluated under the standardized conditions in soil. Accordingly, a laboratory study was conducted to evaluate the characteristics of N release from a bag controlled fertilizer with 1, 3, 5 and 7 rows of hole (B-1, B-3, B-5, B-7) and a kraft bag without hole (B-W). The results showed that the amount of N leaching of B-1, B-3, B-5, B-7 and B-W were significantly lower than urea fertilizer without bag (U). The maximum N release from the fertilizers followed the order: U (83.16%) > B-7 (54.61%) > B-5 (54.02%) > B-W (51.51%) > B-3 (48.87%) > B-1 (38.60%) during the experimentation. Compared with U treatment, ammonia volatilization losses were significantly decreased by B-1, B-3, B-5, B-7 and B-W treatments. Based on N release and loss, a suitable bag with holes should be considered in practice when using the bag controlled fertilizer to meet an environment good objective. The evaluation method merits further study combined with field experiment.


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