Abstract. The aim of this study is to estimate the green and blue water footprint (WF) and the total water use (TWU) of wheat crop in China in both irrigated and rainfed productions. Crop evapotranspiration and water evaporation loss are both considered when calculating the water footprint in irrigated fields. We compared the water use for per-unit product between irrigated and rainfed crops and analyzed the relationship between promoting the yield and conserving water resources. The national total and per-unit-product WF of wheat production in 2010 were approximately 111.5 Gm 3 (64.2 % green and 35.8 % blue) and 0.968 m 3 kg −1 , respectively. There is a large difference in the water footprint of the per-kilogram wheat product (WFP) among different provinces: the WFP is low in the provinces in and around the Huang-Huai-Hai Plain, while it is relatively high in the provinces south of the Yangtze River and in northwestern China. The major portion of WF (80.9 %) comes from irrigated farmland, and the remaining 19.1 % is rainfed. Green water dominates the area south of the Yangtze River, whereas low green water proportions are found in the provinces located in northern China, especially northwestern China. The national TWU and total water use of the per-kilogram wheat product (TWUP) are 142.5 Gm 3 and 1.237 m 3 kg −1 , respectively, containing approximately 21.7 % blue water percolation (BW p ). The values of WFP for irrigated (WFP I ) and rainfed (WFP R ) crops are 0.911 and 1.202 m 3 kg −1 , respectively. Irrigation plays an important role in food production, promoting the wheat yield by 170 % and reducing the WFP by 24 % compared to those of rainfed wheat production. Due to the low irrigation efficiency, more water is needed per kilogram in irrigated farmland in many arid regions, such as the Xinjiang, Ningxia and Gansu Provinces. We divided the 30 provinces of China into three categories according to the relationship between the TWUP I (TWU for per-unit product in irrigated farmland) and TWUP R (TWU for perunit product in rainfed farmland): (I) TWUP I < TWUP R , (II) TWUP I = TWUP R , and (III) TWUP I > TWUP R . Category II, which contains the major wheat-producing areas in the North China Plain, produces nearly 75 % of the wheat of China. The double benefits of conserving water and promoting production can be achieved by irrigating wheat in Category I provinces. Nevertheless, the provinces in this category produce only 1.1 % of the national wheat yield.

Immune stress is the loss of immune homeostasis caused by external forces. The purpose of this experiment was to investigate the effects of immune stress on the growth performance, small intestinal enzymes and peristalsis rate, and mRNA expression of nutrient transporters in broiler chickens. Four hundred and thirty-two 1-d-old broilers (Cobb500) were randomly assigned to four groups for treatment; each group included nine cages with 12 birds per cage. Group 1 = no vaccine (NV); Group 2 = conventional vaccine (CV); group 3 = lipopolysaccharide (LPS)+conventional vaccine (LPS); group 4 = cyclophosphamide (CYP)+conventional vaccine (CYP). The results demonstrated that immune stress by LPS and CYP reduced body weight gain (BWG), feed intake (FI), small intestine peristalsis rate and sIgA content in small intestinal digesta (p<0.05). However, the feed conversion ratio (FCR) remained unchanged during the feeding period. LPS and CYP increased intestinal enzyme activity, relative expression of SGLT-1, CaBP-D28k and L-FABP mRNAs (p<0.05). LPS and CYP injection had a negative effect on the growth performance of healthy broiler chickens. The present study demonstrated that NV and CV could improve growth performance while enzyme activity in small intestine and relative expression of nutrient transporter mRNA of NV and CV were decreased in the conditions of a controlled rational feeding environment. It is generally recommended that broilers only need to be vaccinated for the diseases to which they might be exposed.

No abstract

Water scarcity is a major constraint of agricultural production in arid and semi-arid areas. In the face of future water scarcity, one possible way the agricultural sector could be adapted is to change cropping patterns and make adjustments for available water resources for irrigation. The present paper analyses the temporal evolution of cropping pattern from 1960 to 2008 in the Hetao Irrigation District (HID), China. The impact of changing cropping patterns on regional agricultural water productivity is evaluated from the water footprint (WF) perspective. Results show that the area under cash crops (e.g. sunflower and melon) has risen phenomenally over the study period because of increased economic returns pursued by farmers. Most of these cash crops have a smaller WF (high water productivity) than grain crops in HID. With the increase of area sown to cash crops, water productivity in HID increased substantially. Changing the cropping pattern has significant effects on regional crop water productivity: in this way, HID has increased the total crop production without increasing significantly the regional water consumption. The results of this case study indicate that regional agricultural water can be used effectively by properly planning crop areas and patterns under irrigation water limitations. However, there is a need to foster a cropping pattern that is multifunctional and sustainable, which can guarantee food security, enhance natural resource use and provide stable and high returns to farmers.

The establishment of water-saving crop planning is an inevitable choice of the water-saving agriculture for the water-deficiency region in the arid and semiarid Loess Plateau of China and the world. The water-saving crop planning refers to the planting structure that centres the adjustment of the crop's adaptation to water, the optimization of temporal and spatial layout for crops, the local natural resources, marketing resources, human resources and financial input to enable region or basin with limited water resources to achieve the maximum economic, social and ecological benefits of planting industry under certain technology and economy. After the analysis on the research progress of optimization theory, optimization goals, optimization methods of water-saving cultivation structure and macro-control measures, it is pointed out that the main deficiencies of the current research of water-saving cultivation pattern optimization are lacking of a strong theoretical basis, and the immaturity of optimization technologies. The future crucial research direction will focus on five aspects such as the special optimization theory system, the division methods by studying the watershed unit and using 3S technology, optimization model based on multi-objective evolutionary algorithm, evaluation of rationality and macro-control measures on the basis of the public participation.

Agricultural production is accompanied by a large amount of water consumption, nonpoint source pollution, and greenhouse gas emissions. However, the comprehensive and quantitative analysis of associated impacts on regional water, the environment, and the economy caused by variations in agricultural distribution is insufficient. This paper evaluates the evolution of grain production distribution and its effects on water resources, the economy, and the environment in China by using virtual water theory. The results show that the grain production area located in northern China is characterized by scarce water resources and a less developed economy. Due to the imbalance between grain supply and demand, virtual water embedded in grain will transfer among regions. These flows have formed a pattern where virtual water transfers from the water‐scarce northern region to the water‐rich southern region, increasing from 72.99 Gm3 in 1997 to 124.64 Gm3 in 2014. Evolution of grain production distribution changes the spatial pattern of grain production and consumption, and it exacerbates water resource pressure, the gray water footprint, and greenhouse gas emissions in the area that exports grain virtual water. The gray water footprint and carbon emissions in the grain export area increased by 10.66% and 31.06% during the study period, respectively. Meanwhile, the distribution of regional grain production influences the allocation of water resources in agriculture and other industries. Due to the difference between the economic benefits created by industry and agriculture, grain virtual water flow will have effects on the regional economic development.

We would like to point out that there is a mistake in Eq. (1). This is the correct equation: P e = P (4.17 − 0.02 P )/4.17, P < 83 41.7 + 0.1 P , P ≥ 83 .Published by Copernicus Publications on behalf of the European Geosciences Union.

No abstract