Effects of nitrogen fertilizer, soil temperature and moisture on the soil-surface CO 2 efflux and production in an oasis cotton field in arid northwestern China

Geoderma ◽  
2017 ◽  
Vol 308 ◽  
pp. 93-103 ◽  
Author(s):  
Yongxiang Yu ◽  
Chengyi Zhao ◽  
Hongtao Jia ◽  
Baicheng Niu ◽  
Yu Sheng ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Nitrogen Fertilizer ◽  
Soil Surface ◽  
Northwestern China ◽  
Cotton Field ◽  
Arid Northwestern China ◽  
Soil Temperature And Moisture

scholarly journals Greenhouse Gas Emissions from Cotton Field under Different Irrigation Methods and Fertilization Regimes in Arid Northwestern China

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jie Wu ◽  
Wei Guo ◽  
Jinfei Feng ◽  
Lanhai Li ◽  
Haishui Yang ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Drip Irrigation ◽  
Ghg Emissions ◽  
Northwestern China ◽  
Cotton Field ◽  
Cotton Yield ◽  
Cotton Production ◽  
Production Region ◽  
Irrigation Methods ◽  
Arid Northwestern China

Drip irrigation is broadly extended in order to save water in the arid cotton production region of China. Biochar is thought to be a useful soil amendment to reduce greenhouse gas (GHG) emissions. Here, a field study was conducted to compare the emissions of nitrous oxide (N2O) and methane (CH4) under different irrigation methods (drip irrigation (D) and furrow irrigation (F)) and fertilization regimes (conventional fertilization (C) and conventional fertilization + biochar (B)) during the cotton growth season. The accumulated N2O emissions were significantly lower with FB, DC, and DB than with FC by 28.8%, 36.1%, and 37.6%, while accumulated CH4uptake was 264.5%, 226.7%, and 154.2% higher with DC, DB, and FC than that with FB, respectively. Irrigation methods showed a significant effect on total global warming potential (GWP) and yield-scaled GWP (P<0.01). DC and DB showed higher cotton yield, water use efficiency (WUE), and lower yield-scaled GWP, as compared with FC and FB. This suggests that in northwestern China mulched-drip irrigation should be a better approach to increase cotton yield with depressed GHG. In addition, biochar addition increased CH4emissions while it decreasedN2Oemissions.

scholarly journals Simultaneously assimilating multivariate data sets into the two-source evapotranspiration model by Bayesian approach: application to spring maize in an arid region of northwestern China

2014 ◽  
Vol 7 (4) ◽  
pp. 1467-1482 ◽  
Author(s):  
G. F. Zhu ◽  
X. Li ◽  
Y. H. Su ◽  
K. Zhang ◽  
Y. Bai ◽  
...  
Keyword(s):  
Soil Surface ◽  
Heat Fluxes ◽  
Northwestern China ◽  
Data Sets ◽  
Canopy Interception ◽  
Arid Northwestern China ◽  
Spring Maize ◽  
Direct Measurements ◽  
Land Surfaces

Abstract. Based on direct measurements of half-hourly canopy evapotranspiration (ET; W m−2) using the eddy covariance (EC) system and daily soil evaporation (E; mm day−1) using microlysimeters over a crop ecosystem in arid northwestern China from 27 May to 14 September in 2013, a Bayesian method was used to simultaneously parameterize the soil surface and canopy resistances in the Shuttleworth–Wallace (S–W) model. Four of the six parameters showed relatively larger uncertainty reductions (> 50%), and their posterior distributions became approximately symmetric with distinctive modes. There was a moderately good agreement between measured and simulated values of half-hourly ET and daily E with a linear regression being y = 0.84 x + 0.18 (R2 = 0.83) and y = 1.01 x + 0.01 (R2 = 0.82), respectively. The causes of underestimations of ET by the S–W model was possibly attributed to the microscale advection, which can contribute an added energy in the form of downward sensible heat fluxes to the ET process. Therefore, the advection process should be taken into account in simulating ET in heterogeneous land surfaces. Also, underestimations were observed on or shortly after rainy days, which may be due to direct evaporation of liquid water intercepted in the canopy. Thus, the canopy interception model should be coupled to the S–W model in the long-term ET simulation.

PHYTO-CLIMATIC OBSERVATIONS ENSURING THE INCREASE OF THE COTTON YIELD

2020 ◽  
Vol 57 (08) ◽  
pp. 33-45
Author(s):  
Mahira Aydin Veliyeva ◽  
Keyword(s):  
Soil Temperature ◽  
Growth And Development ◽  
Plant Density ◽  
Research Work ◽  
Soil Surface ◽  
Vegetation Period ◽  
Cotton Field ◽  
Factors Affecting ◽  
Excessive Heat ◽  
Irrigation Regimes

The factors affecting on the decrease of cotton productivity are discussed in the article. With this purpose, the foundation for the research work on the study “Influence of external factors and components of agro-technical cultivation on the degree of falling fruit organs of cotton” was laid in 2011. The research work had been carried out in four-rowed plots with 100 m of length, 12 variants with four-fold repetition. The total area of experimental plot formed 11520 m2. The results of observations and calculations based on studies conducted under three sharply differing irrigation regimes, two plant densities and the use of micro-elements in two periods are analyzed. There are a lot of difficulties in growing a systematically stable crop from cotton fields. One of them is falling of fruit organs. Falling of fruit organs of cotton plant (bud, flower, ovary) due to physiological decline and violation of agro-technical measures forms 50-60% and sometimes more. Falling of fruit organs also depends on hereditary factors. Lack or abundance of moisture content of the soil, unbalanced fertilizers, strong winds, excessive heat, damage by diseases and pests, etc. Reinforce the falling process, which leads to lower yields. An urgent task is to study ways for regulating the global problem - to reduce the fall of the fruit organs in order to increase productivity. The influence of phytoclimate, plant density and microclimate was studied under three different irrigation regimes. Systematic observations over the soil temperature had been conducted from the beginning to the end of the vegetation period. As a result of the study, it was found that the soil under the vegetative layer warms up later. There is a continuous heat exchange between the soil surface and the lower layers. The study of the relationship between the temperature conditions and the growth and development of plants is of great significance in the practice of agricultural crops. For this purpose, the effect of changes in soil temperature on cotton field under the influence of irrigation regimes on productivity, growth and development of plants is determined. The influence of irrigation - the most important element of the complex of agro-technical methods - on change of soil temperature, duration of the each irrigation, soil cooling depth, productiveness, growth and development of plants is studied in the article. Key words: fruit organs, fall, irrigation regime, hard, optimal, high, soil temperature, maximum and minimum temperatures

Embryo dormancy responses to temperature in capeweed (Arctotheca calendula) seeds

2002 ◽  
Vol 12 (3) ◽  
pp. 181-191 ◽  
Author(s):  
Amanda J. Ellery
Keyword(s):  
Soil Temperature ◽  
Water Potential ◽  
Low Temperatures ◽  
Seasonal Changes ◽  
Temperature Fluctuation ◽  
Soil Surface ◽  
Seed Collection ◽  
Embryo Dormancy ◽  
Response To Temperature ◽  
Dormancy Cycles

Changes in embryo dormancy of capeweed [Arctotheca calendula (L.) Levyns.] seeds in response to temperature were investigated to determine the nature of seasonal dormancy cycles. Primary embryo dormancy persisted for 2–3 months after seed collection and was then rapidly relieved when seeds were maintained at temperatures simulating summer soil surface temperatures. Embryo dormancy was also rapidly relieved in seeds maintained at constant temperatures, indicating that a daily temperature fluctuation was not necessary for the relief of embryo dormancy in capeweed. Dormancy relief was maximal at 40°C. Secondary dormancy was induced when seeds were maintained at low temperatures and a water potential of –1.5 MPa, suggesting that the onset of winter may postpone germination until a subsequent autumn. These results indicate that the dormancy cycles observed in capeweed seeds maintained on the soil surface are probably driven by seasonal changes in soil temperature.

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