Effects of Ground Mulching Treatments on Soil Moisture Content in Second-generation Seed Garden of Pinus elliottii

Different ground mulching treatments were designed to observe the effects on soil moisture content in a second-generation seed orchard of Pinus elliottii. The results showed that： （1） there were extreme differences in soil moisture content Ⅰ and soil moisture content Ⅲ, but no obvious difference in soil moisture content II was observed; and （2） the high-to-low order of soil moisture content Ⅰ under different ground mulching treatments was white film〉sawdust〉black film〉the control, and the highest value was higher than the lowest one by 26.69%; the high-to-low order of soil moisture content Ⅱ under different ground mulching treatments was white film〉black film〉sawdust〉the control, and the highest value was higher than the lowest one by 20.64%; and the high-to-low order of soil moisture content Ⅲ under different ground mulching treatments was black film〉white film〉sawdust〉the control, and the highest value was higher than the lowest one by 26.61%.

Effects of Soil Moisture Content and p H on Residual Dynamics of Chlorothalonil in Acidified Soil

[Objective] This study aimed to investigate the residual dynamics of chlorothalonil in acidified soil under different conditions of soil moisture content and pH. [Method] By simulation tests, the effects of different soil moisture content and pH on chlorothalonil residues in acidified soil were analyzed. [Result] Under different conditions of soil moisture content and pH, the residual quantity of chlorothalonil in acidified soil was reduced gradually with the extension of incubation time. To be specific, the reduction rate of chlorothalonil residues in soil was extremely high within the first three days and slightly declined at 3-7 d; after 7 d, the residual quantity of chlorothalonil in soil was reduced slowly and steadily. [Conclusion] This study provides the reference for soil environmental remediation and maintenance of a health cultivation system.

Real-time Monitoring Scheme of Soil Moisture Content in Paddy Field

The monitoring of soil moisture content in paddy field is one of important parts and contents of regional soil moisture monitoring. But a good monitoring scheme hasn’t been established. A real-time monitoring scheme of soil moisture content in paddy field was put forward from two key links of soil moisture content monitoring and field water-layer monitoring. This scheme could meet the alternative monitoring requirements of soil moisture content in water layer and none-water layer. It had a good maneuverability and could provide references for practical work.

A distributed measurement method for in-situ soil moisture content by using carbon-fiber heated cable

Moisture content is a fundamental physical index that quantifies soil property and is closely associatedwith the hydrological, ecological and engineering behaviors of soil. To measure in-situ soil moisturecontents, a distributed measurement system for in-situ soil moisture content （SM-DTS） is introduced.The system is based on carbon-fiber heated cable （CFHC） technology that has been developed to enhancethe measuring accuracy of in-situ soil moisture content. Using CFHC technique, a temperature characteristicvalue （Tt） can be defined from temperatureetime curves. A relationship among Tt, soil thermalimpedance coefficient and soil moisture content is then established in laboratory. The feasibility of theSM-DTS technology to provide distributed measurements of in-situ soil moisture content is verifiedthrough field tests. The research reported herein indicates that the proposed SM-DTS is capable ofmeasuring in-situ soil moisture content over long distances and large areas.

Performance evaluation of two types of heated cables for distributedtemperature sensing-based measurement of soil moisture content

Distributed temperature sensing(DTS)using heated cables has been recently developed for distributed monitoring of in-situ soil moisture content.In this method,the thermal and electrical properties of heated cables have a significant influence on the measurement accuracy of soil moisture content.In this paper,the performances of two heated cables,i.e.the carbon-fiber heated cable(CFHC)and the metalnet heated cable(MNHC),are studied in the laboratory.Their structures,uniformity in the axial direction,measurement accuracy and suitability are evaluated.The test results indicate that the MNHC has a better uniformity in the axial direction than CFHC.Both CFHC and MNHC have high measurement accuracy.The CFHC is more suitable for short-distance measurement(500 m),while the MNHC can be used for longdistance measurement(>500 m).

Influence of soil moisture content on pullout properties of Hippophae rhamnoides Linn. roots

Plant root system plays an important role in preventing soil erosion and improving slope stability.However,its performance is significantly affected by soil moisture content,and the role of soil moisture in root reinforcement is not fully understood.In this study,the influence of soil moisture on root pullout properties was studied by experiments.Vertical in-situ pullout tests under four different levels of soil matric suction(12 kPa,18 kPa,24 kPa,30 kPa)were carried out on roots of sea buckthorn plants(Hippophae rhamnoides Linn.)which were artificially cultivated for 7 months.Diameter and length of the root system of sea buckthorn were investigated.The results showed that a very significant correlation was observed between root diameter(D)and root length(L)(P<0.01),and root diameter decreased with soil depth.When soil bulk density was constant,peak pullout force(F)and friction coefficient of root-soil interface(μ)decreased with increasing gravimetric soil moisture content in power functions.Soil moisture content significantly affected root pullout resistance because the increase of soil moisture content decreased the friction coefficient between the roots and soil.Root diameter at breakage point(Db)and length of root segment left in soil(Lb)were increased with soil moisture content.In addition,peak pullout force of the roots increased in a power function with root diameter at the soil surface(D0)and in a linear function with total root length(L).The results provided an experimental basis for quantifying the effects of soil moisture content on soil reinforcement by plant roots.

Investigating spatial and temporal variations of soil moisture content in an arid mining area using an improved thermal inertia model

Mining operations can usually lead to environmental deteriorations. Underground mining activities could cause an extensive decrease in groundwater level and thus a dramatic variation in soil moisture content（SMC）. In this study, the spatial and temporal variations of SMC from 2001 to 2015 at two spatial scales（i.e., the Shendong coal mining area and the Daliuta Coal Mine） were analyzed using an improved thermal inertia model with a long-term series of Landsat TM/OLI（TM=Thematic Mapper and OLI=Operational Land Imager） data. Our results show that at large spatial scale（the Shendong coal mining area）, underground mining activities had insignificant negative impacts on SMC and that at small spatial scale（the Daliuta Coal Mine）, underground mining activities had significant negative impacts on SMC. Trend analysis of SMC demonstrated that areas with decreasing trend of SMC were mainly distributed in the mined area, indicating that underground mining is a primary cause for the drying trend in the mining region in this arid environment.

Changes in Soil Moisture Content and Characteristics ofWater Movement in Citrus Orchards under Different Mulching Methods

[Objectives]The paper was to explore the effects of different mulching methods on soil moisture content and water movement in citrus orchards,and to provide the theoretical basis for improving water and weed management level in orchards.[Methods]Three ground mulching treatments including spraying herbicide(CK),grass-proof cloth cover(GPC)and natural grass mowing(NGM)were set up to analyze the soil moisture content and water flux characteristics of soil profile in the soil layers of 5,20,40 and 60 cm under different mulching methods.[Results]The GPC and NGM treatments significantly increased the soil moisture content in the soil layer of 0-60 cm at the young fruit stage and fruit expansion stage,which inhibited soil water evaporation and effectively improved soil water holding capacity,thus reducing irrigation water consumption and saving water resources.During the expansion stage of citrus fruits,the soil water flux in the soil layer of 0-60 cm in NGM and CK treatments was upward,and the upward soil water flux in NGM treatment was larger,which could mobilize more upward movement of deep soil moisture for uptake by citrus roots.However,the soil water flux in the soil layer of 0-60 cm in GPC treatment was downward,and the soil moisture conditions in the upper and middle layers were already sufficient for citrus growth.[Conclusions]Both GPC and NGM treatments can increase the overall soil moisture content.In the dry season,the soil moisture content in the upper layer treated by GPC is always relatively high,while more soil water in the lower layer move to the upper layer in NGM treatment,which has met the water requirements for citrus growth.

Does nitrogen application rate affect the moisture content of corn grains?

Nitrogen fertilizer application is an important measure to obtain high and stable corn yield,and the moisture content of corn grains is an important factor affecting the quality of mechanical grain harvesting.In this study,four different nitrogen fertilizer treatments from 0 to 450 kg ha^(–1) pure nitrogen were set for a planting density of 12.0×10^(4) plants ha^(–1) in 2017 and 2018,and 18 different nitrogen fertilizer treatments from 0 to 765 kg ha^(–1) pure nitrogen were set for planting densities of 7.5×10^(4) and 12.0×10^(4) plants ha^(–1) in 2019,to investigate the effect of nitrogen application rate on the moisture content of corn grains.Under each treatment,the growth of corn,leaf area index(LAI)of green leaves,grain moisture content,and grain dehydration rate were measured.The results showed that,as nitrogen application increased from 0 to 765 kg ha^(–1),the silking stage was delayed by about 1 day,the maturity stage was delayed by about 1–2 days,and the number of physiologically mature green leaves and LAI increased.At and after physiological maturity,the extreme difference in grain moisture content between different nitrogen application rates was 1.9–4.0%.As the amount of nitrogen application increased,the corn grain dehydration rate after physiological maturity decreased,but it did not reach statistical significance between nitrogen application rate and grain dehydration rate.No significant correlation was observed between LAI at physiological maturity and grain dehydration rate after physiological maturity.In short,nitrogen application affected the grain moisture content of corn at and after physiological maturity,however,the difference in grain moisture content among different nitrogen application rates was small.These results suggest that the effect of nitrogen application on the moisture content of corn grains should not be considered in agricultural production.

Difference in corn kernel moisture content between pre-and post-harvest

The harvest method of shelling corn(Zea mays L.)kernels in the field decreases labor costs associated with transporting,drying and threshing the crop.However,it was previously found that the kernel moisture content increased after field harvest,which decreased the value of corn kernels.To identify the reasons underlying the increase,we conducted a multiyear and-area trial in the Huang-Huai-Hai Plain,China and performed a staged-harvest test at several phases of kernel dry-down.The test investigated a range of parameters such as the kernel moisture content pre-and post-harvest,the kernel breakage rate,the amount of impurities,and the moisture content of various other plant tissues.An analysis of 411 pairs of pre-and post-harvest samples found that kernel moisture content after harvest was 2.2%higher than that before harvest.In the staged-harvest test,however,a significant increase was only observed when the kernel moisture content before harvest was higher than 23.9%.The increase in post-harvest kernel moisture content was positively associated with the pre-harvest kernel moisture content,breakage rate and impurity rate.Typically,at harvest time in this region,there is a significant fraction of immature crops with a high moisture content,resulting in kernels that are prone to breakage or impurities that ultimately lead to increases in water content after harvest.Therefore,we suggest using hybrids that quickly wither late in the growing stage.Additionally,farmers should delay harvest in order to minimize the pre-harvest kernel moisture content and thus reduce breakages and impurities,thereby improving the quality of kernels after harvest and the efficiency of corn kernel farming in China.

Study of corn kernel breakage susceptibility as a function of its moisture content by using a laboratory grinding method

The rate of corn kernel breakage in the grain combine harvesters is a crucial factor affecting the quality of the grain shelled in the field. The objective of the present study was to determine the susceptibility of corn kernels to breakage based on the kernel moisture content in order to determine the moisture content that corresponds to the lowest rate of breakage.In addition, we evaluated the resistance to breakage of various corn cultivars. A total of 17 different corn cultivars were planted at two different sowing dates at the Beibuchang Experiment Station, Beijing and the Xinxiang Experiment Station(Henan Province) of the Chinese Academy of Agricultural Sciences. The corn kernel moisture content was systematically monitored and recorded over time, and the breakage rate was measured by using the grinding method. The results for all grain samples from the two experimental stations revealed that the breakage rate y is quadratic in moisture content x,y=0.0796 x^(2)-3.3929 x+78.779;R^(2)0=0.2646, n=512. By fitting to the regression equation, a minimum corn kernel breakage rate of 42.62% was obtained, corresponding to a corn kernel moisture content of 21.31%. Furthermore, in the 90% confidence interval, the corn kernel moisture ranging from 19.7 to 22.3% led to the lowest kernel breakage rate, which was consistent with the corn kernel moisture content allowing the lowest breakage rate of corn kernels shelled in the field with combine grain harvesters. Using the lowest breakage rate as the critical point, the correlation between breakage rate and moisture content was significantly negative for low moisture content but positive for high moisture content. The slope and correlation coefficient of the linear regression equation indicated that high moisture content led to greater sensitivity and correlation between grain breakage and moisture content. At the Beibuchang Experiment Station, the corn cultivars resistant to breakage were Zhengdan 958(ZD958) and Fengken 139(FK139), and the corn cultivars non-resistant to breakage were Lianchuang 825(LC825), Jidan 66(JD66), Lidan 295(LD295), and Jingnongke 728(JNK728). At the Xinxiang Experiment Station, the corn cultivars resistant to breakage were HT1, ZD958 and FK139, and the corn cultivars non-resistant to breakage were ZY8911, DK653 and JNK728. Thus, the breakage classifications of the six corn cultivars were consistent between the two experimental stations. In conclusion, the results suggested that the high stability of the grinding method allowed it to be used to determine the corn kernel breakage rates of different corn cultivars as a function of moisture content, thus facilitating the breeding and screening of breakage-resistant corn.

Evaluation of Soil Organic Carbon and Soil Moisture Content from Agricultural Fields in Mississippi

Independent observation of the effects of agricultural management practices on soil organic carbon (SOC) with soil moisture content (SMC) is essential to quantify their potential relationships for sustainable ecosystems. Soil water retention studies and soil carbon stocks have been mapped in some areas worldwide. However, few studies have been conducted in the southeastern US, particularly in Mississippi. The objectives of this research study were to collect soil samples from fields chosen to be representative of the watersheds they are contained within, analyze the soil samples for carbon content and soil moisture content, and evaluate the relationship between SOC and different parameters (land use, vertical distribution, temporal distribution, and soil moisture content). Field sites were chosen based on their compositional similarity shared with the watershed as a whole in the Town Creek watershed (TCW) and Upper Pearl River watershed (UPRW) in Mississippi. Monthly soil samples from different depths (6 inch, 12 inch, and 24 inch) were collected from crop, pasture, and forest field areas. Soil samples were analyzed using bench analysis, elemental analysis, and statistical analysis. This study was able to demonstrate the SOC distribution in the soil layers across all three land uses studied. It was also shown that there does seem to be an interactive effect of parameters such as land use type, vertical distribution, and time on carbon accretion within the soil. Results of this study also determined that the near surface (6-in) layer was found to contain significantly more carbon than either the 12 inch or 24 inch layers (p 0.01) across all field types. There was found to be a high degree of variability within the soil moisture data and correlation between SOC and SMC. It was found that carbon amount is not influenced by SMC but SMC could be influenced by SOC.

Research on the Estimation Model of Soil Moisture Content Based on the Characteristics of Thermal Infrared Data

With the portable Fourier Transform Infrared Spectroscopy (FTIR), the reflectance spectra of soil samples with different moisture content are measured in laboratory for expounding the characteristic of radiation in the thermal infrared part of the spectrum with different soil moisture content. A model of estimating the moisture content in soil is attempted to make based on Moisture Diagnostic Index (MDI). In general,the spectral characteristic of soil emissivity in laboratory includes the following aspects.Firstly,in the region of 8.0-9.5 μm,along with the increase of soil moisture content,the emissivity of soil increases to varying degrees. The spectral curves are parallel relatively and have a tendency to become horizontal and the absorbed characteristic of reststrahlen is also weakened relatively with the increase of soil moisture in this region.Secondly,in the region of 11.0-14.0 μm,the emissivity of soil has a tendency of increasing.There is an absorption value near about 12.7 μm. As the soil moisture content increases,the depth of absorption also increases. This phenomenon may be caused by soil moisture absorption. Methods as derivative, difference and standardized ratio transformation may weaken the background noise effectively to the spectrum data. Especially using the ratio of the emissivity to the average of 8-14 μm may obviously enhance the correlation between soil moisture and soil emissivity. According to the result of correlation analysis, the 8.237 μm is regarded as the best detecting band for soil moisture content. Moreover,based on the Moisture Diagnostic Index ( MDI) in the 8.194-8.279 μm, the logarithmic model of estimating soil moisture is made.

The Agricultural Technology for Manuring and Sowing Simultaneously Applied to Summer Corn "Jinzhengda"

[Objective] The aim was to get a high yield and simplify fertilization of summer corn in moisture soils in the east of Henan province. [Method] Effects of slow-release fertilizers special for summer corn on its yield, economic benefits and resistance. [Result] By the slow-release fertilizers containing 45% slow-release nitrogen, thousand-kernel weight and the number of ear went up by 28 g and 16 kernels, respectively. Slow-release fertilizers advanced nutrient uptake by summer corns and kept soil nitrogen balanced. In comparison to local fertilization approach, corn yield grew by 13.5% and net profit went up by 1 920 yuan/hm^2 by same-term application technique of seed ＆ slow-release fertilizer in comparison to local methods. In comparison to normal fertilizers containing the same-quantity nutrients, corn yield grew by 10.3% and net profit by 1 215 yuan/hm^2. [Conclusion] The research provides references for slow-release fertilizer promotion in production of corn in Zhoukou and innovation and integration between agricultural machines and techniques.

The lateral pressure coefficient at rest of expansive soils in landfill at various vertical stresses and moisture contents

When expansive soils in the original location are artificially transferred to landfill in different seasons,and subject to engineering activities afterwards,the corresponding deformation and stability of retaining structures become unpredictable.This necessitates the determination of lateral pressure coefficient at rest(k_(0) value)for expansive soils in landfill.Considering compaction,excavation of expansive soils,as well as construction of landfill in different seasons,series of stepwise loading and unloading consolidation tests at various moisture contents were carried out in this work to explore the evolution characteristics of k_(0) value and assess the dependence of k_(0) value on vertical stress and moisture content.Besides,scanning electron microscope(SEM)was used to track the change in microstructural features with vertical stresses.The results indicated that the k_(0) value of expansive soil shows a pronounced nonlinearity and is inextricably linked with vertical stress and moisture content,based on which a prediction formula to estimate the variation in k_(0) value with vertical stress during loading stage was proposed;there is a significant exponential increase in k_(0) value with overconsolidation ratio(OCR)during unloading stage,and OCR dominates the release of horizontal stress of expansive soil;SEM results revealed that with an increase in vertical stress,the anisotropy of expansive soil microstructure increases dramatically,causing a significant directional readjustment,which is macroscopically manifested as an initially rapid increase in k_(0) value;but when vertical stress increases to a critical value,the anisotropy of microstructure increases marginally,indicating a stable orientation occurring in the soil microstructure,which causes the k_(0) value to maintain a relatively stable value.

Process Parameter Study on Microwave-assisted Foam-mat Drying Properties of Corn Soaking Water

In order to study the microwave-assisted foam-mat drying properties of corn soaking water and optimize process parameters, a quadratic regression orthogonal rotary method was used to analyze the influence of microwave power, material weight, material thickness and drying time on moisture content（dry basis）, color value and protein content. Results showed that the primary and secondary sequence of parameters with regard to moisture content（d. b.） was drying time, microwave power, material weight and material thickness; the primary and secondary sequence of parameters with regard to color value was material weight, drying time, microwave power and material thickness; the primary and secondary sequence of parameters with regard to protein content was drying time, material weight, microwave power and material thickness. Optimum conditions were obtained as microwave power of 560 W, material weight of 46.88 g, material thickness of 6.20 mm and drying time of 8.01 min. The results might provide the theoretical basis and technical support for the microwave-assisted foam-mat drying of corn soaking water to produce yeast protein power.

Drying Characteristics of Microwave-assisted Foam Drying of Corn Soaking Water

To improve the industrial utilization of corn soaking water, the yeast protein powder was produced by microwave-assisted foam drying. Firstly, preparation experiments were carded out, which included the foaming characteristic experiments of fermentation broth and that about the effects of carbon and nitrogen ratio on solid content in the fermentation broth. Secondly, the drying characteristics experiment of corn soaking water was studied, which selected the microwave power, material amount and thickness as the influencing factors for the single experiment. The results showed that the final moisture content （d.b.） and drying rate were significantly affected by those factors.

Effect of phenophase based irrigation schedules on growth, yield and quality of baby corn (Zea mays L.)

The field experiment was conduced at the Agronomy Field Unit, Main Research Station, University of Agricultural Sciences, Hebbal, Bangalore, India during 2002 and 2003 to study the effect of irrigation schedules on growth, yield and quality of baby corn. The soil of the experimental site was red sandy loam in texture with neutral reaction. The experiment was laid out in a randomized complete block design with three replications. There were seven treatments of irrigation schedules based on IW/CPE ratio of 0.6 and 1.0 during different phenophases of baby corn. The results of the experiment revealed that the baby corn dry matter was significantly higher (75.57 g.plant–1) with higher green fodder yield of 43.47 t.ha–1 due to irrigation scheduled at IW/CPE ratio of 1.0 followed by moisture stress at early stage (I3). Irrigations scheduled at IW/CPE ratio of 1.0 registered significantly higher baby corn yield of 6.60 t.ha–1 followed by the delayed irrigation at early stage of 10 - 25 DAS. Significantly higher crude protein, phosphorus, potassium and lower reducing sugars and ascorbic acid content of baby corn was recorded under IW/CPE ratio of 1.0. Delayed irrigation at 0.6 IW/CPE ratio through-out produced baby corn with higher taste and juiciness. The total crop water use ranged from 294.10 to 469.10 mm, respectively under continuously delayed irrigation at 0.6 IW/CPE ratio and frequent irrigation at IW/CPE ratio of 1.0 which also recorded higher water use efficiency.

Effects of Fertilization on Moisture Content of Soils in the Loess Hilly-gully Region

[Objective] The aim of this study was to study the influence of plants on the soil moisture content under different fertilization.[Method] Using sainfoin,sweet clover,Astragalus adsurgens,alfalfa,ryegrass,little flower,white clover as experimental material,this study explored the effects of soil moisture on the improvement of soil quality.[Result] Results showed that the soil moisture content of different plants follows as：sainfoin 〉sweet clover 〉Astragalus adsurgens 〉alfalfa perennial ryegrass 〉small crown 〉white clover,and the average moisture content reached 24.13% which was 2.45% higher than that of control group.At planting white clover,sweet clover,under the condition of 7 kinds of crops,in the treatments without fertilizer and with organic fertilizer,soil moisture content of soil in 0-20 cm grew significantly.[Conclusion] The application of organic fertilizer and growing of plants would improve soil moisture in abandoned fields,enhance the ability of soil water supply,and improve soil fertility.

Effects of initial soil moisture content on soil water and nitrogen transport under muddy water film hole infiltration

Film hole irrigation has been widely adopted as an effective water-saving irrigation technology in the arid and semiarid areas of China.To investigate the effects of initial soil moisture content(θ0)on soil water and nitrogen transport characteristics under muddy water film hole infiltration,the laboratory experiments were conducted with muddy water film hole infiltration,using five initial soil moisture content treatments.The models for describing the relationships between the cumulative infiltration(I(t))and infiltration duration(t);the relationship among the horizontal and vertical migration distances of the wetting front(Fx,Fz),θ0 and t,were established.The results showed that the initial soil moisture content had a significant effect on I(t),Fx,Fz and moisture content distribution in the wetted body.The change of I(t)over t conformed to Kostiakov model.With the increase ofθ0,the infiltration coefficient(K)gradually decreased.NO-3-N was mainly distributed in the range of the wetting radius of 15 cm,while NH+4-N was mainly distributed in the range of the wetting radius of 8 cm.This study can provide a theoretical basis and technical support for film hole irrigation.