Scenario-Based Assessment of the Water-Energy-Food Nexus in Kuwait: Insights for Effective Resource Management

The interdependency among water, food, and energy (WEF) in the GCC countries is strongly and closely interlinked, and is intensifying as demand for resources increases with population growth and changing consumption patterns, and are expected to be further compounded by the impacts of climate change. Therefore, integrated management of the three sectors is crucial to reduce trade-offs and build synergies among them. This paper presents a comprehensive framework to assess the WEF nexus in Kuwait as a representative case for the GCC countries. The framework consists of three main steps: 1) evaluating the influence of socio-economic development and climate change on water, energy, and food resources;2) generating scenario-based projections;and 3) conducting an extensive quantitative nexus analysis. The WEF interlinkages in Kuwait are modelled quantitatively using the Q-Nexus model, and current critical interdependencies are evaluated. Then, various WEF-Nexus scenarios were conducted for the year 2035 to explore the effects of management interventions in one sector on the other two sectors. The main findings are that per capita municipal water consumption is a major influencer on the WEF-nexus due to the heavy reliance on thermal desalination in municipal water supply in Kuwait, which is attributed to its energy intensity, financial cost, GHGs emissions, and environmental impacts on the marine and air environments. To reduce WEF trade-offs, mitigate risks, and build synergies among the three sectors, it is important to shift the current policy focus on supply-side management approach to the demand-side management and efficiency approaches.

Quantitative Analysis of the Coupling Coordination Degree Between Urbanization and Eco-environment in Mongolia

Mongolia is an important country in the Economic Corridor of China-Mongolia-Russia, a deep understanding of the coupling relationship between urbanization and the eco-environment in Mongolia is meaningful to achieve green development of the Belt and Road. The entropy method and coupling coordination degree model were integrated to evaluate the coupling coordination degree between urbanization and the eco-environment in Mongolia during 2000-2016. The results showed that the coupling coordination degree between urbanization and the eco-environment in Mongolia was generally at the stage of seriously unbalanced development, and that the main contributor of the urbanization and the eco-environment subsystem were demographic urbanization and eco-environment endowment, respectively. The southern part of Mongolia central zone should be paid more attention due to the lower degree of coupling coordination between urbanization and the eco-environment. To promote the healthy urbanization development in Mongolia, six-layer eco-city establishing green development pattern is proposed to provide scientific support for Mongolia.

Rainfall erosivity and sediment dynamics in the Himalaya catchment during the Melamchi flood in Nepal

Rainfall erosivity is an indicator of rainfall potential to cause soil erosion.The Melamchi extreme flood occurred on June-15 and recurred on July-31,2021 in Nepal.During these flooding events,a large volume of sediments were eroded,transported and deposited due to the high rainfall erosivity of the basin.In this study,the temporal and the spatial distribution of rainfall erosivity within the Melamchi River Basin was estimated and further linked to sediment discharge and concentration at various sites along the river segments.The daily rainfall data for the event year 2021 of the entire basin were used.Validation was performed by post-flooding grain size sampling.The result showed that rainfall and rainfall erosivity exhibit pronounced intensity within the Melamchi River basin,particularly at Sermathang and Tarkeghang,both located in the middle section of the basin.The average annual rainfall in the Melamchi region was 3140.39 mm with an average annual erosivity of 18302.06(MJ mm)/(ha h yr).The average daily erosivity of the basin was 358.67(MJ mm)/(ha h)during the first event and 1241(MJ mm)/(ha h)for the second event.In the upper section of sampling,the sediment size ranged from 0.1 mm to>8 mm and was poorly graded.However,the lower region had smaller sediment ranging from 0.075 mm to>4.75 mm and also well graded.The smaller size(<1 mm)sediment passing was much higher in the Chanaute(78%)and Melamchi(66.5%)river segments but the larger size(>100 mm)sediments were passed relatively higher from the Kiwil(8.20%)and Ambathan(8.39%)river segments.During premonsoon and monsoon seasons,the highest sediment concentration was found to be 563.8 g/L and 344.3 g/L in Bhimtar and the lowest was 238.5 g/L and 132.1 g/L at the Ambathan,respectively.The sediment concentration during the pre-monsoon was found to be higher than the sediment concentration during the monsoon season in the Melamchi River.The more erosive regions in the basin were associated with the presence of highly fractured rock,weathered rocks and a thrust(weak)zone.The higher rainfall erosivity at upstream and the higher sediment concentration at downstream during flooding events have coincided well in the basin.Thus,the estimation of rainfall erosivity at the catchment scale and its influences on sediment concentration in the river are crucial for erosion control measures during flooding times in the Himalaya.

Combining rhizosphere and soil-based P management decreases the P fertilizer demand of China by more than half based on LePA model simulations

Phosphorus(P)is a finite natural resource and is increasingly considered to be a challenge for global sustainability.Agriculture in China plays a key role in global sustainable P management.Rhizosphere and soil-based P management are necessary for improving P-use efficiency and crop productivity in intensive agriculture in China.A previous study has shown that the future demand for phosphate fertilizer by China estimated by the LePA model(legacy phosphorus assessment model)can be greatly reduced by soil-based P management(the building-up and maintenance approach).The present study used the LePA model to predict the phosphate demand by China through combined rhizosphere and soil-based P management at county scale under four P fertilizer scenarios:(1)same P application rate as in 2012;(2)rate maintained same as 2012 in low-P counties or no P fertilizer applied in high-P counties until targeted soil Olsen-P(TPOlsen)level is reached,and then rate was the same as P-removed at harvest;(3)rate in each county decreased to1–7 kg ha^(-1) yr^(-1) after TPOlsen is reached in low-P counties,then increased by 0.1–9 kg ha^(-1) yr^(-1) until equal to P-removal;(4)rate maintained same as 2012 in low-P counties until TPOlsen is reached and then equaled to P-removal,while the rate in high-P counties is decreased to 1–7 kg ha^(-1) yr^(-1) until TPOlsen is reached and then increased by 0.1–9 kg ha^(-1) yr^(-1)until equal to P-removal.Our predictions showed that the total demand for P fertilizer by whole China was 693 Mt P2O5and according to scenario 4,P fertilizer could be reduced by 57.5%compared with farmer current practice,during the period 2013–2080.The model showed that rhizosphere P management led to a further 8.0%decrease in P fertilizer use compared with soil-based P management.The average soil Olsen-P level in China only needs to be maintained at 17 mg kg^(-1) to achieve high crop yields.Our results provide a firm basis for government to issue-relevant policies for sustainable P management in China.

Optimizing integrative cultivation management improves grain quality while increasing yield and nitrogen use efficiency in rice

A major challenge in rice(Oryza sativa L.)production is to cope with increasing grain yield and fertilizer use efficiency without compromising grain quality.This study was designed to determine if optimizing integrative cultivation management in rice could improve grain quality while increase yield and nitrogen use efficiency(NUE).An indica-japonica hybrid rice cultivar and a japonica rice cultivar were grown in the field,with five cultivation managements including no N application(0 N),local farmer's practice(LFP),and three optimizi ng in teg rati ve cultivati on managements,reducing N rate and increasi ng plant density(ND),ND+alternate wetting and moderate soil drying irrigation(NDW),and NDW+applying rapeseed cake fertilizer(NDWR).The results showed that the optimizi ng integrative cultivati on man ageme nts could not only in crease grain yield,but also enhance NUE compared to LFP.Compared to LFP,NDWR sign ifica ntly in creased brow n,milled,head milled rice rate,ratio of the kern el le ngth to breadth and breakdown value of starch,whereas decreased amylose content,gel consiste ncy,prolamin con tent,setback value,perce ntage of chalky kern els,and chalki ness.The three optimizing in tegrative cultivation managements increased con tents of total protei ns,albumin and glutelin,activities of the key enzymes involved in the sucrose-starch con version in grains,root oxidati on activity,and malic and succinic acid concentrations in root exudates during the grain-filling period.The results suggested that optimizing integrative cultivation managements could improve grain quality meanwhile increase grain yield and NUE by enhancing physiological activities of rice plants.

Characterization and Evaluation of OsLCT1 and OsN ramp5 Mutants Generated Through CRISPR/Cas9-Mediated Mutagenesis for Breeding Low Cd Rice

To explore how rice(Oryza sativa L.) can be safely produced in Cd-polluted soil, OsLCT1 and OsNramp5 mutant lines were generated by CRISPR/Cas9-mediated mutagenesis. One of OsLCT1 mutant(lct1×1) and two of OsNramp5 mutants(nramp5×7 and nramp5×9) were evaluated for grain Cd accumulation and agronomic performances. In paddy field soil containing approximately 0.9 mg/kg Cd, lct1×1 grains contained approximately 40%(0.17 mg/kg) of the Cd concentration of the wild type parental line, less than the China National Food Safety Standard(0.20 mg/kg). Both OsNramp5 mutants showed low grain Cd accumulation(< 0.06 mg/kg) in the paddy(approximately 0.9 mg/kg Cd) or in pots in soil spiked with 2 mg/kg Cd. However, only nramp5×7 showed normal growth and yield, whereas the growth of nramp5×9 was severely impaired. The study showed that lct1×1 could be used to produce rice grains safe for human consumption in lightly contaminated paddy soils and nramp5×7 used in soils contaminated by much higher levels of Cd.

Impact of land cover types on the soil characteristics in karst area of Chongqing

The 26 plots including natural forestland, secondary forestland, shrub-grassland, sloping cropland, artificial forest and abandoned field, were selected to discuss the impact of land cover on the soil characteristics in the three karst districts of Chongqing. The results showed that： （1） After the vegetation turned into secondary vegetation or artificial vegetation, or reclamation, soil physical properties would be degraded. In the surface-layer soil of sloping cropland, the contents of 〉2 mm water-stable aggregates decreased obviously with apparent sandification. （2） The contents of soil organic matter and total nitrogen are controlled completely by vegetation type and land use intensity. The increasing trend is rather slow in the early days when over-reclamation is stopped and the land is converted to forest and pasture. （3） Herbaceous species increase and woody plants species decrease with the increase of land use intensity, therefore, the soil seed banks degrade more seriously. （4） The soil degradation index has been set up to describe the relative soil degradation degree under the conditions of different vegetation types. （5） Land cover has a significant effect on karst soil characteristics, land degradation in the karst ecosystem is essentially characterized by the different degradation of soil functions that serve as water banks, nutrient banks and soil seed banks.

Efficiency of sample-based indices for spatial pattern recognition of wild pistachio(Pistacia atlantica) trees in semi-arid woodlands

The efficiency of sample-based indices proposed to quantify the spatial distribution of trees is influenced by the structure of tree stands, environmental heterogeneity and degree of aggregation. We evaluated 10 commonly used distance-based and 10 density-based indices using two structurally different stands of wild pistachio trees in the Zagros woodlands, Iran, to assess the reliability of each in revealing stand structure in woodlands. All trees were completely stem-mapped in a nearly pure（40 ha） and a mixed（45 ha） stand. First, the inhomogeneous pair correlation function [g（r）] and the Clark-Evans index（CEI） were used as references to reveal the true spatial arrangement of all trees in these stands. The sampled data were then evaluated using the 20 indices.Sampling was undertaken in a grid based on a square lattice using square plots（30 m 9 30 m） and nearest neighbor distances at the sample points. The g（r） and CEI statistics showed that the wild pistachio trees were aggregated in both stands, although the degree of aggregation was markedly higher in the pure stand. Three distance- and six density-based indices statistically verified that the wild pistachio trees were aggregated in both stands. The distance-based Hines and Hines statistic（ht） and the densitybased standardised Morisita（Ip）, patchiness（IP） and Cassie（CA） indices revealed aggregation of the trees in the two structurally different stands in the Zagros woodlands and the higher clumping in the pure stand, whereas the other indices were not sensitive enough.

Delineation and Scale Effect of Precision Agriculture Management Zones Using Yield Monitor Data Over Four Years

In this study, precision agriculture management zones were delineated using yield data over four years from the combine harvester equipped with yield monitor and DGPS receiver. Relative yields measured during each year were interpolated to 4 m2 grid size using ordinary kriging. The resultant interpolated yield maps were averaged across years to create a map of the mean relative yield, which was then used for cluster analysis. The mean yield map of post-classification was processed by applying majority filtering with window sizes that were equivalent to the grid sizes of 12, 20, 28, 36, 44, 52 and 60 m. The scale effect of management zones was evaluated using relative variance reduction, test of significant differences of the means of yield zones, spatial fragmentation, and spatial agreement. The results showed that the post-classification majority filtering （PCMF） eliminated lots of isolated cells or patches caused by random variation while preserving yield means, high variance reduction, general yield patterns, and high spatial agreement. The zoned result can be used as yield goal map for preplant or in-season fertilizer recommendation in precision agriculture.

Soil Microbial Metabolic Quotient in Inner Mongolian Grasslands: Patterns and Influence Factors

Microbial metabolic quotient(MMQ) is the rate of soil microbial respiration per unit of microbial biomass, and represents the capacity of soil microbes to utilize soil organic matter.Understanding the regional variation and determinants of MMQ can help predict the responses of soil respiration rate to global climate change.Accordingly, we measured and analyzed MMQ-related data(e.g., soil basic respiration rate at 20℃ and soil microbial biomass) from 17 grassland sites, which located in meadow steppe, typical steppe, and desert steppe along a 1000-km transect across the Inner Mongolian grasslands, China.Results showed that MMQ varied significantly among the different grassland types(P < 0.05;desert > typical > meadow) and decreased from southwest to northeast(r =–0.81) with increasing latitude(r = – 0.50), and with increasing mean annual precipitation(r = –0.69).Precipitation accounted for 56% of the total variation in MMQ, whereas temperature accounted for 26%.MMQ was negatively correlated with precipitation across the Inner Mongolian grasslands.Therefore, climate change, especially in regard to precipitation, may influence soil microbial respiration and soil carbon dynamics through altering MMQ.These results highlighted the importance of spatial patterns in MMQ for accurately evaluating the responses of soil respiration to climate change at regional and global scales.

Paleoclimate evolution and aridification mechanism of the eastern Tethys during the Callovian–Oxfordian: evidence from geochemical records of the Qiangtang Basin, Tibetan Plateau

Global climate during the Jurassic has been commonly described as a uniform greenhouse climate for a long time.However,the climate scenario of a cool episode during the Callovian-Oxfordian transition following by a warming trend during the Oxfordian(163.53 to157.4 Ma)is documented in many localities of the western Tethys.It is still unclear if a correlatable climate scenario also occurred in the eastern Tethys during the same time interval.In this study,a detailed geochemical analysis on the 1060 m thick successions(the Xiali and Suowa formations)from the Yanshiping section of the Qiangtang Basin,located in the eastern Tethys margin during the Callovian-Oxfordian periods,was performed.To reveal the climate evolution of the basin,carbonate content and soluble salt concentrations(SO_(4)^(2-),Cl^(-))were chosen as climatic indices.The results show that the overall climate patterns during the deposition of the Xiali and Suowa formations can be divided into three stages:relatively humid(164.0 to 160.9 Ma),dry(160.9 to159.6 Ma),semi-dry(159.6 to 156.8 Ma).A similar warming climate scenario also occurred in eastern Tethys during the Callovian-Oxfordian transition(160.9 to159.6 Ma).Besides,we clarify that the Jurassic True polar wander(TPW),the motion of the lithosphere and mantle with respect to Earth’s spin axis,inducing climatic shifts were responsible for the aridification of the Qiangtang Basin during the Callovian-Oxfordian transition with a review of the paleolatitude of the Xiali formation(19.7+2.8/-2.6°N)and the Suowa formation(20.7+4.1/-3.7°N).It is because the TPW rotations shifted the East Asia blocks(the North and South China,Qiangtang,and Qaidam blocks)from the humid zone to the tropical/subtropical arid zone and triggered the remarkable aridification during the Middle-Late Jurassic(ca.165-155 Ma).

Delineation of homogeneous forest patches using combination of field measurements and LiDAR point clouds as a reliable reference for evaluation of low resolution global satellite data

Backgrounds： There are many satellite systems acquiring environmental data on the world. Acquired global remote sensing datasets require ground reference data in order to calibrate them and assess their quality. Regarding calibration and validation of these datasets with broad geographical extents, it is essential to register zones which might be considered as Homogeneous Patches （HPs）. Such patches enable an optimal calibration of satellite data/sensors, and what is more important is an analysis of components which significantly influence electro-magnetic signals registered by satellite sensors. Methods： We proposed two structurally different methods to identify HPs： predefined thresholding-based one （static one）, and statistical thresholding-based technique （dynamic one）. In the first method, 3 different thresholds were used： 5%, 10%, and 20%. Next, it was aimed to assess how delineated HPs were spatially matched to satellite data with coarse spatial resolution. Selected cell sizes were 25, 50, 100, 250, and 500 m. The number of particular grid cells which almost entirely fell into registered HPs was counted （leaving 2% cell area tolerance level）. This procedure was executed separately for each variant and selected structural variables, as well as for their intersection parts. Results： The results of this investigation revealed that ALS data might have the potential in the identification of HPs of forest stands. We showed that different ALS based variables and thresholds of HPs definition influenced areas which can be treated as similar and homogeneous. We proved that integration of more than one structural variable limits size of the HPs, in contrast, visual interpretation revealed that inside such patches vegetation structure is more constant. Conclusions： We concluded that ALS data can be used as a potential source of data to ＂enlarge＂ small ground sample plots and to be used for evaluation and calibration of remotely sensed datasets provided by global systems with coarse spatial resolutions.

Physiological Traits and Metabolites of Cacao Seedlings Influenced by Potassium in Growth Medium

Cacao (Theobroma cacao L.) is of significant economic importance in several tropical countries but its yield potentials are low mainly because of poor soil fertility especially low levels of potassium (K). Cacao has a high demand for K to maintain healthy growth and production. Knowledge of K use in cacao will help the development of suitable crop management practices and will aid breeding varieties adapted to environments with a limited soil K supply. Using a plant growth chamber, we investigated the growth and physiological traits among three cacao varieties at three levels of growth medium K (52, 156, and 469 mg·plant-1). Significant K effects were observed on growth traits including stem diameter, root length, chlorophyll b, and the ratio of chlorophyll a/b. Significant K effect was also found on carbohydrate metabolites, such as fructose, glucose, myo-inositol, raffinose and starch. However, no K effect was observed in other growth and physiological indicators, including biomass of seedling and net photosynthetic rate. There were significant genotype differences on seedling growth indicators, including stem diameter, stem height, total biomass, leaf biomass, leaf area, root length, chlorophyll a + b and carotenoids. Genotype difference was also found on all measured carbohydrate and starch metabolites, except maltose and raffinose. Results of this study indicate that although K plays a critical role in cacao tree growth and productivity, cacao may be less sensitive to K deficiency during the seedling stage. The present results improved our understanding about K and plants interaction in cacao seedlings, which is useful for crop management and germplasm utilization.

Effects of microtopography on spatial point pattern of forest stands on the semi-arid Loess Plateau,China

Microtopography may affect the distribution of forests through its effect on rain redistribution and soil water distribution on the semi-arid Loess Plateau,China.In this study,we investigated the characteristics of microtopography on two shady slopes（slope A,5 hm2,uniform slope;slope B,5 hm2,microtopography slope） and surveyed the height,the diameter at breast height and the location（x,y coordinates） of all selected individual trees（Robinia pseudoacacia Linn.,Pyrus betulifolia Bunge,Populus hopeiensis Hu ＆ Chow,Armeniaca sibirica Lam.,Populus simonii Carr.and Ulmus pumila Linn.） on slope A and slope B in the watersheds of Wuqi county,Shaanxi province.Subsequently,the effects of microtopography on the spatial pattern of forest stands were analyzed using Ripley＇s K（r） function.The results showed that：（1） The maximal aggregation radiuses of the tree species on the uniform slope（slope A） were larger than 40 m,whereas those of the tree species on the microtopography slope（slope B） were smaller than 30 m.（2） On slope B,the spatial association of R.pseudoacacia with P.betulifolia,A.sibirica,P.simonii and U.pumila varied from being strongly negative to positive at microtopography scales.The spatial association of Populus hopeiensis Hu ＆ Chow with U.pumila also varied from being strongly negative to positive at microtopography scales.However,there was no spatial association between P.betulifolia and P.hopeiensis,P.betulifolia and A.sibirica,P.betulifolia and P.simonii,P.betulifolia and U.pumila,P.hopeiensis and A.sibirica,P.hopeiensis and P.simonii,A.sibirica and P.simonii,A.sibirica and U.pumila,and P.simonii and U.pumila.On slope A,the spatial association between tree species were strongly negative.The results suggest that microtopography may shape tree distribution patterns on the semi-arid Loess Plateau.

Effect of Se-S Cooperated Application on the Mineral Content and Nutrition Quality of Garlic （Allium Sativum L.）

Eleven nutrition elements and 5 quality elements of garlic （Allium sativum L.） in different Se, S level and their interaction pot experiments were analyzed by atom absorbing spectrophotometer, titration and fixing sulfur method. The mineral elements were analyzed by the Principal Component Analysis and the Factor Analysis on the SPSS 10.0 and three main factors were picked. The results showed that Se, S and Se-S cooperated application enhanced the garlic nutrition quality by increasing mineral nutrition. The garlic Vc was the highest after using higher Se compared middle S level （S 20 mg/kg soil ＋ Se 40 mg/kg soil）. Lower Se level compared middle S level （S 40 mg/kg soil ＋ Se 20 mg/kg soil） get the highest garlic abio-Se in all treatments. The garlic organic Se content was the highest after using higher Se compared middle S （S 40 mg/kg soil ＋ Se 40 mg/kg soil）. The treatment lower S compared lower Se level get the highest garlic allicin in all treatment. It showed that the fresh eating factor was affected by the element Se. The flavor factor and health care factor were affected by both Se and S.

Effect of different fertilization on spring cabbage (<i>Brassica oleracea L. var. capitata</i>) production and fertilizer use efficiencies

Just after transplanting, the vegetable has difficulty in nutrients uptake. To explore the effect of different fertilization on spring cabbage (Brassica oleracea L. var. capitata) production and fertilizer use efficiencies, this experiment consisting of six treatments was implemented and divided into three groups: 1) no fertilizer (NF) and vegetable planting fertilizer (VPF);2) conventional fertilizer (CF) and conventional fertilizer + vegetable planting fertilizer (CVPF);3) reduced fertilizer application (RFA) and reduced fertilizer application + vegetable planting fertilizer (RVPF). The results of this experiment indicated that the yields of spring cabbage treated by VPF increased by 38.20% in VPF, 16.00% in CVPF and 20.40% in RVPF than their controls respectively. Additionally, the VPF helped improve the total and economic yields of the spring cabbage in all groups, and the economic benefits increased by 38.21% in VPF, 15.97% in CVPF and 20.42% in RVPF than their controls respectively. Finally, the VPF was of benefit to spring cabbage to exploit the soil nutrients and helped improve the chemical fertilizer use efficiencies. Therefore, it is an efficient, economical and ecological fertilization for vegetable production to apply chemical fertilizers in combination with VPF.

Finite-thickness effect of the fluids on bubbles and spikes in Richtmyer–Meshkov instability for arbitrary Atwood numbers

This paper investigates the finite-thickness effect of two superimposed fluids on bubbles and spikes in Richtmyer–Meshkov instability(RMI) for arbitrary Atwood numbers by using the method of the small parameter expansion up to the second order. When the thickness of the two fluids tends to be infinity, our results can reproduce the classical results where RMI happens at the interface separating two semi-infinity-thickness fluids of different densities. It is found that the thickness has a large influence on the amplitude evolution of bubbles and spikes compared with those in classical RMI. Based on the thickness relationship of the two fluids, the thickness effect on bubbles and spikes for four cases is discussed. The thickness encourages(or reduces)the growth of bubbles or spikes, depending on not only Atwood number, but also the relationship of the thickness ratio of the heavy and light fluids, which is explicitly determined in this paper.

Interactions between phosphorus availability and microbes in a wheat–maize double cropping system:A reduced fertilization scheme

Mechanisms controlling phosphorus(P) availability and the roles of microorganisms in the efficient utilization of soil P in the wheat–maize double cropping system are poorly understood.In the present study,we conducted a pot experiment for four consecutive wheat–maize seasons(2016–2018) using calcareous soils with high(30.36 mg kg^(–1)) and low(9.78 mg kg^(–1)) initial Olsen-P content to evaluate the effects of conventional P fertilizer application to both wheat and maize(Pwm) along with a reduced P fertilizer application only to wheat(Pw).The microbial community structure along with soil P availability parameters and crop yield were determined.The results showed that the Pw treatment reduces the annual P input by 33.3% without affecting the total yield for at least two consecutive years as compared with the Pwm treatment in the high Olsen-P soil.Soil water-soluble P concentrations in the Pw treatment were similar to those in the Pwm treatment at the 12-leaf collar stage when maize requires the most P.Furthermore,the soil P content significantly affected soil microbial communities,especially fungal communities.Meanwhile,the relative abundances of Proteobacteria and alkaline phosphatase(ALP) activity of Pw were significantly higher(by 11.4 and 13.3%) than those of Pwm in soil with high Olsen-P.The microfloral contribution to yield was greater than that of soil P content in soil with high Olsen-P.Relative abundances of Bacillus and Rhizobium were enriched in the Pw treatment compared with the Pwm treatment.Bacillus showed a significant positive correlation with acid phosphatase(ACP) activity,and Rhizobium displayed significant positive correlations with ACP and ALP in soil with high Olsen-P,which may enhance P availability.Our findings suggested that the application of P fertilization only to wheat is practical in high P soils to ensure optimal production in the wheat and maize double cropping system and that the soil P availability and microbial community may collaborate to maintain optimal yield in a wheat–maize double cropping system.

Temporal Dynamics of Standardized Precipitation Evapotranspiration Index and Its Influence to Summer Maize Yield from Kaifeng Region in He’nan Province

Many quantitative studies get more and more attention on drought occurrence and monitoring trends of drought change using different methods;however few studies involve correlation between drought and crop yield especially drought index. This study analyzed the climate change about annual mean SPEI-3, SPEI-6 and SPEI-12, of Kaifeng region in the period of 1961-2013. The SPEI-3 and SPEI-6 seasonal short timescales showed a decreasing tendency, especially rapidly a decline since 2004, and high-frequency alternate dry/wet periods occurred during 1961-2013. However, the annual timescale SPEI-12 showed almost no evidently rise/decline tendency but severity events of dry/wet episode aggravated in terms of duration and magnitude and remarkable low-frequency change. Correlation analysis results between maize yield from Kaifeng region and multi-month scale annual SPEI showed a high negative significant correlation with -0.689 (ρ ρ < 0.001) in June SPEI-3. Further analysis between maize yield and temperature, precipitation and light during June-September found that precipitation in June and August was the main limiting factor to maize yield and their correlation values were well below the correlation of SPEI-3 of June. Finally, the reconstruction equation found that there was a better change consistency between the maize yield reconstruction and actual production but more error in extremely high and low annual yield. This study provides a reliable analysis of climate change to corn yield and basic data support for services of grain production and food security in the future.

Problems in the Biogas Construction in Weihui City and Development Strategies

Taking the demonstration biogas construction city in Henan Province-Weihui City as the survey and research city, we give an overview of the industrial and agricultural base and current situation of biogas development in Weihui City, and analyze the main problems in biogas construction, such as simple development mode of biogas adopted by rural households, laggard construction of large and medium-sized biogas projects, unsound service system for biogas development and failure to comprehensively use biogas resources. According to the practical work experience, we sum up the following.