Optimizing field management to promote the ecologicalization of agriculture in loess hilly-gully region,China

Scientific field management is an important path to realize ecological production and sustainable development of agriculture.As the main content of field management,nitrogen(N)management is the key to balance the economic and ecological benefits of agricultural production.In the loess hilly-gully region,for the fragile ecological and social system,ecologicalization of agricultural production is an important direction to promote sustainable agricultural development.However,irrational fertilization has been one of the main constraint factors,hindering the ecologicalization of local agriculture.In order to solve the problem and prove the practical significance of field management to ecologicalization of agriculture,this study aimed at evaluating the effects of different N fertilization rates and timing using Root Zone Water Quality Model(RZWQM)and then optimizing the N management.Experiments were conducted from 2018 to 2019 in Yangjuangou watershed,loess hilly-gully region,to calibrate and validate the model.The root mean square error(RMSE)of soil water content,nitrate N concentration,above-ground biomass,leaf area index ranged from 10.5-13.5 mm,2.96-3.80 mg·kg^(−1),730.3-1273.9 kg·ha^(−1)and 0.26-0.38,respectively,with the agreement index(d)between observed and simulated values ranging between 0.88 to 0.98.Simulation results showed that N leaching in semi-arid areas was also quite high due to concentrated rainfall and loose soil,which had previously been neglected.When the fertilization rate decreased by 35%(applying the chemical fertilizer at rate of 245.7 kg N ha^(−1))of typical fertilization(applying the chemical fertilizer at rate of 378.0 kg N ha^(−1)),the leaching and residual N decreased by 72.2%-75.4%and 35.6%-50.9%,respectively,while NUE increased by 41.5%-45.2%with no reduction in maize yield.Additionally,compared with applying additional N at seedling stage in one batch,applying at seedling and jointing stages in two batches further decreased N leaching and improved NUE.Thus,a 35%reduction of typical fertilization rate combined with applying additional N at seedling and jointing stages is recommended.From the perspective of N management,this study demonstrated optimizing field management can play a positive role in the ecologicalization of agriculture,and more field management measures should be explored.

Key Technical Points of Wheat Moisture-resistant Strain Sowing and Management of Promoting Seedlings from Weak to Strong in Daiyue District

According to the meteorological conditions of sowing period and the characteristics of seedling in each key growth period,the measures of rushing drainage,rushing harvest stubble,rushing sow,implementing late sowing,strengthening field management before winter and in spring are taken in Daiyue District during the autumn planting period of wheat,which reduce the influence of natural disasters and increase the yield of wheat.

Advanced Management in Dong Hetang Oil Field

ＡｄｖａｎｃｅｄＭａｎａｇｅｍｅｎｔｉｎＤｏｎｇＨｅｔａｎｇＯｉｌＦｉｅｌｄＴｈｅＤｏｎｇＨｅｔａｎｇｏｉｌｆｉｅｌｄｉｎＴａｒｉｍｂａｓｉｎｏｆＸｉｎｊｉａｎｇｒｅｇｉｏｎｉｓｍｅｄｉｕｍｉｎｓｉｚｅ．ｗｉｔｈｏｉｌｐｒｏｄｕｃｔｉｏｎｏｆ６０００...

Review of Research Situation of Brassica oleracea var.italica

Broccoli(Brassica oleracea var.italica),also called green broccoli,green cauliflower,and calabrese,belongs to genus Brassica in family Cruciferae,and is annual or biennial herbaceous plant.Both broccoli and cauliflower are varieties of Brassica oleracea L.Broccoli is rich in nutrients.Its protein,amino acids and vitamins are higher than cauliflower,and broccoli is easy to grow,the supply period is long,and it has a good market and economic value.This paper introduced broccoli-related information from broccoli's nutritional value,cultivation techniques,existing problems and prospects.In addition,on the basis of existing studies,it discussed the future development prospects of broccoli,in order to promote the production research of broccoli in China.

Priorities for the development of alfalfa pasture in northern China

Alfalfa(Medicago sativa L.)is acclaimed as“Queen of forages”because of its great yield and high feeding value.China is the second biggest country in acreage of alfalfa cultivation,but the cultivation regions of alfalfa are distinguished by adverse climatic and edaphic conditions in northern China.Moreover,the lack of elite alfalfa varieties with great adaptation and poor field management are vital factors limiting development of alfalfa pasture in China.In addition,nutritional quality of alfalfa in China is also poor compared to that in countries of developed animal husbandry industrial.Here,we propose several priorities in terms of a comprehensive system of alfalfa breeding,field management,harvest and processing with Chinese characteristics,based on the theories and methodologies of breeding science,agronomy,plant physiology and agricultural machinery.Implementation of these priorities will greatly contribute to the sustainable development of the alfalfa pasture in China.

Image detection and verification of visual navigation route during cotton field management period

In order to meet the actual operation demand of visual navigation during cotton field management period,image detection algorithm of visual navigation route during this period was investigated in this research.Firstly,for the operation images under natural environment,the approach of color component difference,which is applicable for cotton field management,was adopted to extract the target characteristics of different regions inside and outside cotton field.Secondly,the median filtering method was employed to eliminate noise in the images and realize smoothing process of the images.Then,according to the regional vertical cumulative distribution graph of the images,the boundary characteristic of the cotton seedling region was obtained and the central position of the cotton seedling row was determined.Finally,the detection of the candidate points cluster was realized,and the navigation route was extracted by Hough transformation passing the known point.The testing results showed that the algorithms could rapidly and accurately detect the navigation route during cotton field management period.And the average processing time periods for each frame image at the emergence,strong seedling,budding and blooming stages were 41.43 ms,67.83 ms,68.80 ms and 74.05 ms,respectively.The detection has the advantage of high accuracy,strong robustness and fast speed,and is simultaneously less vulnerable to interference from external environment,which satisfies the practical operation requirements of cotton field management machinery.

The effect of different agricultural management practices on irrigation efficiency, water use efficiency and green and blue water footprint

This paper explores the effect of varying agricultural management practices on different water efficiency indicators: irrigation efficiency(IE), crop water use efficiency(WUE), and green and blue water footprint(WF). We take winter wheat in an experimental field in Northern China as a case study and consider a dry, average and wet year. We conducted 24 modeling experiments with the Aqua Crop model, for all possible combinations of four irrigation techniques, two irrigation strategies and three mulching methods. Results show that deficit irrigation most effectively improved blue water use, by increasing IE(by 5%) and reducing blue WF(by 38%), however with an average 9% yield reduction. Organic or synthetic mulching practices improved WUE(by 4% and 10%, respectively)and reduced blue WF(by 8% and 17%, respectively), with the same yield level. Drip and subsurface drip irrigation improved IE and WUE, but drip irrigation had a relatively large blue WF. Improvements in one water efficiency indicator may cause a decline in another. In particular,WUE can be improved by more irrigation at the cost of the blue WF. Furthermore, increasing IE, for instance by installing drip irrigation, does not necessarily reduce the blue WF.

THE PREDICTION OF WATER AND SALT REGIME IN SALTAFFECTED AREAS BY NUMERICAL SIMULATION

The study of water and salt movement in soil is of vital importance to the prevention of secondary salinization, the reclamation of salt-affected soil and the scheduling of rational irrigation and drainage. In this paper, on the basis of numerical simulation, the processes of salt accumulation and leaching of salts in soils under the conditions of evaporation, rainfall infiltration and irrigation are studied. The numerical methods for the prediction of water and salt regime are investigated.