scholarly journals Urea Application Rate for Crop Straw Decomposition in Temperate China

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Y. Wang ◽  
H. Wang ◽  
C. Gao ◽  
P. A. Seglah ◽  
Y. Bi

Returning straw to the field has become the most important straw utilization method in China. The aim of this research was to study the appropriate amount of nitrogen fertilizer applied when returning the straw of three major crops (wheat, rice, and corn) to the field in areas under low to high yield levels based on the demand of nitrogen for microbial decomposition of straw. Under the condition of returning 100% straw to the field, we developed the formula for calculating the nitrogen application rate and estimated the urea application rate for the three major grain crops. The results showed that returning straws of wheat, early-season rice, middle-season rice and late-season rice, and corn to the field with urea application at the rate of about 150 kg/ha, 120~135 kg/ha, 75 kg/ha, and 75~90 kg/ha, respectively, can provide sufficient nitrogen for microbial decomposition. The urea application rate for returning 100% wheat straw to the field in Huang-Huai-Hai region, Middle-Lower Yangtze region, Loess plateau region, and Northwest arid region was 135–230 kg/ha, 110–190 kg/ha, 85–145 kg/ha, and 95–165 kg/ha, respectively. 52.5–98.5 kg/ha of urea was used for 100% early rice straw returning to the field in Middle-Lower Yangtze region and South China. In addition, the urea application rate for 100% middle-late rice straw returning to the field was 95–180 kg/ha, 100–185 kg/ha, 95–175 kg/ha, and 75–140 kg/ha, respectively. The rate of urea application for 100% corn straw returning to the field in Northeast China, Huang-Huai-Hai, Northwest arid region, and Southwest China was 60–135 kg/ha, 50–115 kg/ha, 60–135 kg/ha, and 45–105 kg/ha, respectively. The amount of nitrogen fertilizer required for the total return of crop straw is not only affected by crop straw C : N, yield per unit area, and ratio of grass to grain but also affected by straw returning mode, regional nitrogen application level, and other factors. Therefore, the amount of nitrogen fertilizer should be adjusted according to the type of cropping system, soil, and climatic conditions of the specific location. This substantial N input for stimulating straw decomposition may favor N losses with nitrate leaching and nitrous oxide emissions and hold a potential for soil N eutrophication in the long term if the level is not carefully adjusted to the N requirement of the subsequent crops and changes in soil organic matter levels.

Agriculture ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1298
Author(s):  
Fumiaki Takakai ◽  
Mimori Goto ◽  
Haruki Watanabe ◽  
Keiko Hatakeyama ◽  
Kentaro Yasuda ◽  
...  

The effects of autumn plowing and lime nitrogen application on rice straw decomposition, CH4 and N2O emission and rice growth in the following year in a high-yielding rice cultivated paddy field were evaluated for two years. The experimental plots were set up, combining different times of rice straw (750 g m−2) incorporation into the soil by plowing (autumn or the following spring), with and without lime nitrogen application in autumn (5 g-N m−2). Autumn plowing promoted the decomposition of rice straw, but the application of lime nitrogen did not show a consistent trend. The soil pH was high (7.3) at the studied site, and the alkaline effect of lime nitrogen may not have been significant. As with straw decomposition, CH4 emissions were suppressed by autumn plowing, and no effect from the lime nitrogen application was observed. It was also suggested that the straw decomposition period may be shorter and the CH4 emissions may be higher in high-yielding cultivars that require a longer ripening period than in normal cultivars. The effect of both treatments on N2O emission was not clear. Both the autumn plowing of rice straw and lime nitrogen application were effective in promoting rice growth and increasing rice yield.


1986 ◽  
Vol 107 (3) ◽  
pp. 573-578 ◽  
Author(s):  
E. O. Lucas

SummarFARZ 27, a high-yield maize variety, was grown in 1984 and 1985 over a wide range of density treatments (1·9– 11·1 plants/m2) and with four rates of nitrogen application (0, 75, 100 and 150 kg N/ha) in Ibadan. south-western Nigeria.There was no significant density or fertilizer effect on morphological characters of number of leaves per plant, height or stem diameter. For total dry-matter yield, the highest density of planting gave the highest yield although less dry matter was obtained in the 1985 experiment than in the 1984 experiment. Optimum density for grain production in both years was 8·8 plants/m2. There is an indication that there is no need to increase density of planting of maize beyond 80000 plants/ha in the south-western part of Nigeria. Plants without applied nitrogen fertilizer gave significantly lower total dry-matter and grain yields than plants with applied nitrogen. Highest grain yield was obtained with 150 kg N/ha in both years. By doubling the nitrogen application rate from the present recommended level of 75 kg N/ha to 150 kg N/ha an average increase of 0·42t/ha of maize was obtained in both years. With the present prices of fertilizer and maize, this increase is economical. It seems therefore that more revenue would accrue to the farmers by using 150 kg N/ha on the ‘FARZ series’ of maize instead of the present recommendation of 75 kg N/ha.


Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3415
Author(s):  
Jinsai Chen ◽  
Guangshuai Wang ◽  
Abdoul Kader Mounkaila Hamani ◽  
Abubakar Sunusi Amin ◽  
Weihao Sun ◽  
...  

Long−term excessive nitrogen fertilizer input has resulted in several environmental problems, including an increase in N2O emissions and the aggravation of nitrate leaching; monitoring nitrogen fertilizer is crucial for maize with high yield. This study aimed to optimize the amount of nitrogen applied to maize by Climate−Smart Agriculture (CSA) so as to continuously improve agricultural productivity and reduce or eliminate N2O emissions as much as possible. Field experiments with a completely randomized design were conducted to examine the effects of six nitrogen treatments (N application levels of 0, 120, 180, 240, 300, 360 kg·ha−1, respectively) on N2O emissions, residual concentration of nitrate and ammonium nitrogen, maize yield, and nitrogen utilization efficiency in 2018 and 2019. The results indicated that the residual concentration of nitrate nitrogen (NO3-−N) in the two seasons significantly increased; N2O emissions significantly increased, and the nitrogen fertilizer agronomic efficiency and partial productivity of maize fell dramatically as the nitrogen application rate increased. The maize grain yield rose when the N application amount was raised (N application amount <300 kg·ha−1) but decreased when the N application amount > 300 kg·ha−1. An increase in the nitrogen application rate can decrease nitrogen use efficiency, increase soil NO3-−N residual, and N2O emissions. Reasonable nitrogen application can increase maize yield and reduce N2O emissions and be conducive to improving nitrogen use efficiency. By considering summer maize yield, nitrogen use efficiency, and farmland ecological environment, 173.94~178.34 kg N kg·ha−1 could be utilized as the nitrogen threshold for summer maize in the North China Plain.


Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 480
Author(s):  
Sarah A. Porter ◽  
David E. James

The size and density of concentrated animal feeding operations have grown significantly over the past twenty-five years, raising concern over the ability of the surrounding landscape to sustainably handle the byproducts of animal agriculture. A novel geographic information system program was developed to spatially model the application of manure nutrients to proximal agricultural fields. Nutrient losses during storage and field application were accounted for to determine the amount of manure sourced nitrogen available annually for land application. By-field nitrogen requirements were estimated using six-year crop rotations and commonly used guidelines on fertilizer recommendations for agronomic crops. Three different nitrogen fertilizer recommendation approaches, ranging from economically optimized rates on the low end to yield goal-driven rates on the high end, were modeled to gauge the sensitivity of the analysis approach to varying nitrogen application rates. For each fertilizer N rate, three manure haul distance scenarios were modeled, allowing for manure travel distance to be capped at distances unique to each livestock type. Lastly, commercial nitrogen fertilizer sales data were combined with manure sourced nitrogen estimates to assess statewide agricultural nitrogen application. Results indicated minimal (<5%) over-application from manure alone when applied at recommended rates and using the haul distances specified. However, regardless of which application rate guidelines were used, combined manure and commercial fertilizer nitrogen exceeded statewide crop requirements (110%–155%). This suggests that significant application of nitrogen above recommended rates is likely occurring. Information on commercial fertilizer application at the field level is sparse, precluding greater understanding of the relative contribution of manure and commercial sources. Despite this knowledge gap, additional focus should be placed on cumulative nitrogen application in areas with dense animal concentrations. Adequate crediting of all nitrogen sources, including the recognition of manure as a valuable fertilizer resource, presents the opportunity for substantial producer cost savings and potential widespread reduction in the contamination of water resources.


2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiucheng He ◽  
Huizhen Qiu ◽  
Kuizhong Xie ◽  
Yucai Wang ◽  
Juan Hu ◽  
...  

AbstractIsatis indigotica planting is the backbone of the medicinal industry in Hexi Oasis, Gansu. In order to solve the problems insufficient water resources and excessive application of nitrogen fertilizer in this area, this paper explored the irrigation and nitrogen levels that can meet the multiple goals of Isatis indigotica. The two-factor split-plot field experiment (2018‒2019) was conducted in Minle County, Gansu Province, China, which contains 9 treatments. There were three levels of irrigation water: W1(low), W2(medium), and W3(high). The soil moisture contents were 60–70%, 70–80%, and 80–90% of the field water-holding capacity, respectively. The nitrogen application rate was classified into three levels, N1(low), N2(medium) and N3(high), which were 150, 200 and 250 kg N/ha, respectively. The standard local irrigation water amount and nitrogen application rate corresponded to W3N3. The results showed that the yield of Isatis indigotica increased first and then decreased with the increase of irrigation amount and nitrogen application rate, the yield of W2N2 is 12.2–17.1% higher than that of W1N1, the yield of W3N3 was 12.1–17.5% lower than that of W2N2. Saving water and reducing nitrogen can improve the quality of Isatis indigotica, compared with W3N3, the indigo, indirubin, (R,S)-epigoitrin and polysaccharides of W2N2 increased by 4.5–5.9%, 2.7–3.1%, 5.2–6.0%, and 1.8–2.1%, respectively. With the increase of nitrogen application rate, the water use efficiency (WUE) first increased and then decreased, as the irrigation volume increases, WUE decreases. Compared with W3N3, the WUE of W2N2 increased by 24.3–27.2%. With the increase of water input, the nitrogen fertilizer use efficiency (NUE) first increased and then decreased, as the nitrogen application rate increases, NUE decreases. Compared with W3N3, the NUE of W2W2 increased by 31.8–34.5%. Therefore, W2N2 can improve quality and increase water and nitrogen utilization efficiency on the basis of ensuring yield.


2021 ◽  
Vol 270 ◽  
pp. 108194
Author(s):  
John Snider ◽  
Glendon Harris ◽  
Phillip Roberts ◽  
Calvin Meeks ◽  
Daryl Chastain ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document