A Full-Scale Optimization of a Crop Spatial Planting Structure and its Associated Effects

Driven by the concept of agricultural sustainable development,crop planting structure optimization(CPSO)has become an effective measure to reduce regional crop water demand,ensure food security,and protect the environment.However,traditional optimization of crop planting structures often ignores the impact on regional food supply–demand relations and interprovincial food trading.Therefore,using a system analysis concept and taking virtual water output as the connecting point,this study proposes a theoretical CPSO framework based on a multi-aspect and full-scale evaluation index system.To this end,a water footprint(WF)simulation module denoted as soil and water assessment tool–water footprint(SWAT-WF)is constructed to simulate the amount and components of regional crop WFs.A multi-objective spatial CPSO model with the objectives of maximizing the regional economic water productivity(EWP),minimizing the blue water dependency(BWFrate),and minimizing the grey water footprint(GWFgrey)is established to achieve an optimal planting layout.Considering various benefits,a fullscale evaluation index system based on region,province,and country scales is constructed.Through an entropy weight technique for order preference by similarity to an ideal solution(TOPSIS)comprehensive evaluation model,the optimal plan is selected from a variety of CPSO plans.The proposed framework is then verified through a case study of the upper–middle reaches of the Heihe River Basin in Gansu province,China.By combining the theory of virtual water trading with system analysis,the optimal planting structure is found.While sacrificing reasonable regional economic benefits,the optimization of the planting structure significantly improves the regional water resource benefits and ecological benefits at different scales.

Integrated model simulates bigger, sweeter tomatoes under changing climate under reduced nitrogen and water input

When simulating the response of fruit growth and quality to environmental factors and cultivation practices,the interactions between the mother plant and fruit need to be considered as a whole system.Here,we developed the integrative Tomato plant and fruit Growth and Fruit Sugar metabolism(TGFS)model by coupling equations describing the biophysical processes of leaf gas exchange,water transport,carbon allocation,organ growth and fruit sugar metabolism.The model also accounts for effects of soil nitrogen and atmospheric CO_(2) concentration on gaseous exchange of water and carbon by the leaf.With different nitrogen and water input values,TGFS performed well at simulating the dry mass of the tomato leaf,stem,root,and fruit,and the concentrations of soluble sugar and starch in fruit.TGFS simulations showed that increasing air temperature and CO_(2) concentration has positive effects on fruit growth,but not on sugar concentrations.Further model-based analyses of cultivation scenarios suggest that,in the context of climate change,decreasing N by 15%–25%and decreasing irrigation by 10%–20%relative to current levels would increase tomato fresh weight by 27.8%–36.4% while increasing soluble sugar concentration by up to 10%.TGFS provides a promising tool to optimise N and water inputs for sustainable high-quality tomatoes.

Effects of deficit irrigation with saline water on spring wheat growth and yield in arid Northwest China

Field experiments were conducted in 2008 and 2009 to study the effects of deficit irrigation with saline water on spring wheat growth and yield in an arid region of Northwest China. Nine treatments included three salinity levels sl, s2 and s3 （0.65, 3.2, and 6.1 dS/m） in combination with three water levels wl, w2 and w3 （375, 300, and 225 mm）. In 2008, for most treatments, deficit irrigation showed adverse effects on wheat growth; meanwhile, the effect of saline irrigation was not apparent. In 2009, growth parameters of wl treatments were not always optimal under saline irrigation. At 3.2 and 6.1 dS/m in 2008, the highest yield was obtained by wl treatments, however, in 2009, the weight of 1,000 grains and wheat yield both followed the order w2 〉 wl 〉 w3. In this study, spring wheat was sensitive to water deficit, especially at the booting to grain-filling stages, but was not significantly affected by saline irrigation and the combination of the two factors. The results demonstrated that 300-mm irrigation water with a salinity of less than 3.2 dS/m is suitable for wheat fields in the study area.

Effects of irrigation and nitrogen management on hybrid maize seed production in north-west China

Scientific irrigation and nitrogen management is important for agricultural production in arid areas. To quantify the effect of water and nitrogen management on yield components, biomass partitioning and harvest index(HI) of maize for seed production with plastic filmmulching, field experiments including different irrigation and N treatments were conducted in arid north-west China in 2013 and 2014. The results indicated that kernel number per plant(KN) was signi ficantly affected by irrigation and N treatments. However, 100-kernel weight was relatively stable. Reducing irrigation quantity signi ficantly increased stem partitioning index(PI_(stem)) and leaf partitioning index(PIl_(eaf)), and decreased ear partitioning index(PI_(ear)) at harvest, but lowering Nrate(from 500 to 100 kg N$hm^(–2))did not signi ficantly reduce PI_(stem), PI leaf, andPIl_(eaf) at harvest. HI was signi ficantly reduced by reducing irrigation quantity, but not by reducing Nrate. Linear relationships were found between KN, PI_(stem), PI leaf,PIl_(eaf) at harvest and HI and evapotranspiration(ET).

Alternate partial root-zone irrigation with high irrigation frequency improves root growth and reduces unproductive water loss by apple trees in arid north-west China

Alternate partial root-zone irrigation(APRI)can improve water use efficiency in arid areas. However,the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use have not been reported. A two-year field experiment was conducted with two irrigation amounts(400 and500 mm) and three irrigation methods(conventional irrigation, APRI with high and low frequencies). Root length density, stomatal conductance, photosynthetic rate,transpiration rate, leaf water use efficiency, midday stem and leaf water potentials were measured. The results show that in comparison with conventional irrigation, APRI with high frequency significantly increased root length density and decreased water potentials and stomatal conductance.No differences in the above indicators between the two APRI frequencies were detected. A significantly positive relationship between stomatal conductance and root length density was found under APRI. Overall, alternate partial root-zone irrigation with high frequency has a great potential to promote root growth, expand water uptake capacity and reduce unproductive water loss in the arid apple production area.

Animal stem cells: the engineering development front of 2018

The Engineering Fronts reports are important guidelines for the future development directions of engineering science and technology. The Chinese Academy of Engineering (CAE) has been conducting studies relevant to Engineering Fronts for two years since 2017.

Modeling of hydrological processes in arid agricultural regions

Understanding of hydrological processes,including consideration of interactions between vegetation growth and water transfer in the root zone,underpins efficient use of water resources in arid-zone agriculture.Water transfers take place in the soil-plant-atmosphere continuum,and include groundwater dynamics,unsaturated zone flow,evaporation/transpiration from vegetated/bare soil and surface water,agricultural canal/surface water flow and seepage,and well pumping.Models can be categorized into three classes:(1)regional distributed hydrological models with various land uses,(2)groundwater-soil-plant-atmosphere continuum models that neglect lateral water fluxes,and(3)coupled models with groundwater flow and unsaturated zone water dynamics.This review highlights,in addition,future research challenges in modeling arid-zone agricultural systems,e.g.,to effectively assimilate data from remote sensing,and to fully reflect climate change effects at various model scales.

Comparison of evapotranspiration and energy partitioning related to main biotic and abiotic controllers in vineyards using different irrigation methods

Knowledge of evapotranspiration(ET)and energy partitioning is useful for optimizing water management,especially in areas where water is scarce.A study was undertaken in a furrow-irrigated vineyard(2015)and a drip-irrigated vineyard(2017)in an arid region of northwest China to compare vineyard ET and energy partitioning and their responses to soil water content(SWC)and leaf area index(LAI).ET and soil evaporation(E)and transpiration(T)were determined using eddy covariance,microlysimeters,and sap flow.Seasonal average E/ET,T/ET,crop coefficient(Kc),evaporation coefficient(Ke),and basal crop coefficient(Kcb)were 0.50,0.50,0.67,0.35,and 0.29,respectively,in the furrow-irrigated vineyard and 0.42,0.58,0.57,0.29,and 0.43 in the dripirrigated vineyard.The seasonal average partitioning of net radiation(Rn)into the latent heat flux(LE),sensible heat flux(H)and soil heat flux(G)(LE/Rn,H/Rn,and G/Rn),evaporative fraction(EF)and Bowen ratio(β)were 0.57,0.26,0.17,0.69 and 0.63,respectively,in the furrowirrigated vineyard and 0.46,0.36,0.17,0.57 and 0.97 in the drip-irrigated vineyard.The LE/Rn,H/Rn,EF,andβwere linearly correlated with LAI.The E,Kc,Ke,E/ET,LE/Rn,LEs/Rn(ratio of LE by soil E to Rn),H/Rn,EF andβwere closely correlated with topsoil SWC(10 cm depth).Responses of ET and energy partitioning to the LAI and SWC differed under the two irrigation methods.Drip irrigation reduced seasonal average E/ET and increased average T/ET.From the perspective of energy partitioning,seasonal average H/Rn increased whereas LE/Rn,especially LEs/Rn,decreased.Compared with furrow irrigation,drip irrigation decreased the proportion of unproductive water consumption thereby contributing to enhanced water use efficiency and accumulation of dry matter.

Invitation to Contribute to Frontiers of Agricultural Science and Engineering

Colleagues,It is our great pleasure to introduce you to the Frontiers of Agricultural Science and Engineering(FASE),a new international journal launched in 2014.FASE was founded jointly by the Chinese Academy of Engineering,China Agricultural University and

Invitation to Contribute to Frontiers of Agricultural Science and Engineering

Colleagues,It is our great pleasure to introduce you to the Frontiers of Agricultural Science and Engineering(FASE), a new international journal launched in 2014. FASE was founded jointly by the Chinese Academy of Engineering, China Agricultural University and Higher Education Press of China.

Invitation to Contribute to Frontiers of Agricultural Science and Engineering

Colleagues,It is our great pleasure to introduce you to the Frontiers of Agricultural Science and Engineering(FASE),a new international journal launched in 2014.FASE was founded jointly by the Chinese Academy of Engineering,China Agricultural University and

Invitation to Contribute to Frontiers of Agricultural Science and Engineering

Colleagues,It is our great pleasure to introduce you to the Frontiers of Agricultural Science and Engineering(FASE),a new international journal launched in 2014.FASE was founded jointly by the Chinese Academy of Engineering,China Agricultural University and Higher Education Press of China.

Invitation to Contribute to Frontiers of Agricultural Science and Engineering

Colleagues,It is our great pleasure to introduce you to the Frontiers of Agricultural Science and Engineering(FASE),a new international journal launched in 2014.FASE was founded jointly by the Chinese Academy of Engineering,China Agricultural University and Higher Education Press of China.

Invitation to Contribute to Frontiers of Agricultural Science and Engineering

Colleagues,It is our great pleasure to introduce you to the Frontiers of Agricultural Science and Engineering(FASE),a new international journal launched in 2014.FASE was founded jointly by the Chinese Academy of Engineering,China Agricultural University and Higher Education Press of China.

Invitation to Contribute to Frontiers of Agricultural Science and Engineering

Colleagues,It is our great pleasure to introduce you to the Frontiers of Agricultural Science and Engineering(FASE),a new international journal launched in 2014.FASE was founded jointly by the Chinese Academy of Engineering,China Agricultural University and Higher Education Press of China.

Invitation to Contribute to Frontiers of Agricultural Science and Engineering

Colleagues,It is our great pleasure to introduce you to the Frontiers of Agricultural Science and Engineering(FASE),a new international journal launched in 2014.FASE was founded jointly by the Chinese Academy of Engineering,China Agricultural University and Higher Education Press of China.