Experimental study on radiation utilization efficiency and soil temperature in paddy field with different irrigation methods in Northeast China

Cultivated land use layout adjustment (CLULA) based on crop planting suitability is the refinement and deepening of land use transformation, which is of great significance for optimizing the allocation of cultivated land resources and ensuring food security. At present, people rarely consider the land suitability of crops when using cultivated land, resulting in an imbalance between crop distribution and resource conditions such as water, heat, and soil, and adversely affects the ecological security and utilization efficiency of cultivated land. To alleviate China’s grain planting structural imbalance and efficiency loss, this paper based on the planting suitability of main food crops (rice, soybean, and maize) to adjust and optimize the cultivated land use layout (CLUL) in the typical counties of the main grain production area in Northeast China, using the agent-based model for optimal land allocation (AgentLA) and GIS technology. Findings from the study show that: (1) The planting suitability of rice, soybean, and maize in the region is obviously different. Among them, the suitability level of soybean and maize is high, and that of rice is low. The current CLUL of the food crops needs to be further optimized and adjusted. (2) By optimizing the layout of rice, soybean, and maize, the planting suitability level of the food crops and the concentration level of the CLUL spatial pattern have been improved. (3) The plan for CLULA is formulated: The study area is divided into rice stable production area, maize-soybean rotation area, maize dominant area, and soybean dominant area, and town or village is identified as the implementation unit of CLULA. The plan for CLULA will be conducive to the concentrated farming of food crops according to the suitable natural conditions and management level. The research realized the optimization of spatial structure and cultivated land use patterns of different food crops integrating farming with protecting land. The significance of the study is that it provides a scientific basis and guidance for adjusting the regional planting structure and solving the problem of food structural imbalance.

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Experimental study on the thermal imbalance and soil temperature recovery performance of horizontal stainless-steel ground heat exchanger

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2021.117697 ◽

2021 ◽

pp. 117697

Author(s):

Lingling Xu ◽

Liang Pu ◽

Angelo Zarrella ◽

Derun Zhang ◽

Shengqi Zhang

Keyword(s):

Experimental Study ◽

Stainless Steel ◽

Heat Exchanger ◽

Soil Temperature ◽

Ground Heat Exchanger ◽

Temperature Recovery ◽

Recovery Performance ◽

Thermal Imbalance

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Annual Variation in Soil Enzyme Activity in a Paddy Field: Soil Temperature and Nutrient Availability Are Important for Controlling Enzyme Activities

Applied and Environmental Soil Science ◽

10.1155/2018/4093219 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Takashi Kunito ◽

Takashi Shiroma ◽

Hitoshi Moro ◽

Hirotaka Sumi

Keyword(s):

Acid Phosphatase ◽

Soil Temperature ◽

Nutrient Availability ◽

Paddy Field ◽

Enzyme Activities ◽

N Availability ◽

Field Soil ◽

Allocation Model ◽

Total N ◽

Glucosidase Activity

Annual variations in enzyme activities involved in carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) cycling and soil physicochemical properties were examined in a Japanese paddy field. All the enzyme activities determined at the field soil temperature (range, 2.2°C–28.3°C) increased exponentially with soil temperature (p<0.001). Significant negative correlations were found between Bray-2P concentration and the ratio of acid phosphatase to β-D-glucosidase activity (Spearman r = −0.631, p = 0.005) and between total N and the ratio of L-asparaginase to β-D-glucosidase activity (r = −0.612, p=0.007), suggesting that in accordance with the resource allocation model, acid phosphatase and L-asparaginase were synthesized by microorganisms depending on the temporal changes in soil P and N availability. These results suggest the significance of soil temperature in controlling in situ enzyme activities in paddy soil and also that the stoichiometry of enzyme activities associated with C, N, and P acquisition reflects the soil nutrient availability.

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Experimental Study on the Fractal Features and Permeability Characteristics of Low Metamorphic Coal Pore Structure under Thermal Damage

Geofluids ◽

10.1155/2020/8864571 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13

Author(s):

Zhen Liu ◽

Mingrui Zhang ◽

Shijian Yu ◽

Lin Xin ◽

Gang Wang ◽

...

Keyword(s):

Experimental Study ◽

Pore Structure ◽

Coal Gasification ◽

Thermal Damage ◽

Fractal Model ◽

Utilization Efficiency ◽

Heating Process ◽

Underground Coal Gasification ◽

External Temperature ◽

Permeability Characteristics

Underground coal gasification and exploitation of geothermal mine resources can effectively improve coal conversion and utilization efficiency, and the basic theory of the above technologies generally relies on the change law of the coal pore structure under thermal damage. Therefore, the influence mechanism of the development of the coal pore structure under thermal damage is analyzed by the nuclear magnetic resonance experiment, and the temperature-permeability fractal model is created. The results show that compared with microtransitional pores, the volume of meso-macropores in the coal body is more susceptible to an increase in temperature, which was most obvious at 200-300°C. During the heating process, the measured fractal dimension based on the T2 spectral distribution is between 2 and 3, indicating that the fractal characteristics did not disappear upon a change in external temperature. The temperature has a certain negative correlation with DmNMR, DMNMR, and DNMR, indicating that the complexity of the pore structure of the coal body decreased gradually with the increase of the temperature. Compared with the permeability calculated based on the theoretical permeability fractal model, the permeability obtained from the temperature-permeability fractal model has a similar increasing trend as the permeability measured by the NMR experiment when the temperature increases. The experimental study on pore structure and permeability characteristics of the low metamorphic coal under thermal damage provides a scientific theory for underground coal gasification and geothermal exploitation.

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Effect of tillage and crop residue on soil temperature following planting for a Black soil in Northeast China

Scientific Reports ◽

10.1038/s41598-018-22822-8 ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 9

Author(s):

Yan Shen ◽

Neil McLaughlin ◽

Xiaoping Zhang ◽

Minggang Xu ◽

Aizhen Liang

Keyword(s):

Soil Temperature ◽

Northeast China ◽

Crop Residue ◽

Black Soil

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Methane emission by plant communities in an alpine meadow on the Qinghai-Tibetan Plateau: a new experimental study of alpine meadows and oat pasture

Biology Letters ◽

10.1098/rsbl.2009.0123 ◽

2009 ◽

Vol 5 (4) ◽

pp. 535-538 ◽

Cited By ~ 22

Author(s):

Shiping Wang ◽

Xiaoxia Yang ◽

Xingwu Lin ◽

Yigang Hu ◽

Caiyun Luo ◽

...

Keyword(s):

Experimental Study ◽

Soil Temperature ◽

Plant Communities ◽

Alpine Meadow ◽

Pore Space ◽

Bare Soil ◽

Chemical Mechanism ◽

Limited Evidence ◽

Growing Seasons ◽

Water Filled Pore Space

Recently, plant-derived methane (CH 4 ) emission has been questioned because limited evidence of the chemical mechanism has been identified to account for the process. We conducted an experiment with four treatments (i.e. winter-grazed, natural alpine meadow; naturally restored alpine meadow eight years after cultivation; oat pasture and bare soil without roots) during the growing seasons of 2007 and 2008 to examine the question of CH 4 emission by plant communities in the alpine meadow. Each treatment consumed CH 4 in closed, opaque chambers in the field, but two types of alpine meadow vegetation reduced CH 4 consumption compared with bare soil, whereas oat pasture increased consumption. This result could imply that meadow vegetation produces CH 4 . However, measurements of soil temperature and water content showed significant differences between vegetated and bare soil and appeared to explain differences in CH 4 production between treatments. Our study strongly suggests that the apparent CH 4 production by vegetation, when compared with bare soil in some previous studies, might represent differences in soil temperature and water-filled pore space and not the true vegetation sources of CH 4 .

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