Til Feike

Development of agricultural land and water use and its driving forces along the Aksu and Tarim River, P.R. China

Abstract The extremely arid Aksu-Tarim Region (ATR) in northwestern China is one of the country’s most important cotton production bases. However, in recent years, the negative ecological consequences of the intensive agricultural production become apparent. Apart from the degradation of riparian vegetation, competition for scarce water resources among farmers tightens. To be able to develop solutions for the aggravating problems, and sustain the ATR as a favored agricultural production base, it is decisive to clearly understand the land- and water-use development and its driving forces in the ATR. Statistical yearbook data from 1989 to 2011, comprising the four administrative regions of the ATR, namely Aksu and Bayangol prefectures, as well as Division 1 and Division 2 of the military farms, and annual producer price data constitute the data base for the present study. Relevant policy documents and data obtained through a stakeholder workshop complement the analysis. It is shown that agricultural land area more than doubled during the 1989–2011 period. This is a result of the interaction of: (1) vast population growth and related increase in agricultural labor; (2) positive price developments for fruits and cotton; (3) strong increase in agricultural profitability, triggering further land reclamation; (4) afforestation programs pushing for the establishment of orchards; and (5) insufficient restriction of agricultural land expansion. It is recommended to step up the efforts to move people out of agriculture into other sectors, and significantly improve agricultural water productivity by increasing yield levels and shifting crop production towards labor-intensive high-value commodities.

Irrigation in the Tarim Basin, China: farmers’ response to changes in water pricing practices

The extremely arid Tarim Basin in northwestern China is an important cotton and fruit production region. However, extensive agricultural land reclamation combined with unreasonable water use in recent decades resulted in degradation of ecosystems along the Tarim River. With declining water availability, it is becoming increasingly important to utilize this essential resource more efficiently. Water pricing is considered an effective way to advance water allocation and water conservation. To identify whether a strong increase in water price may lead to a wiser agricultural water use along Tarim River, 128 farmers were interviewed with structured questionnaire in different parts of the Basin. Multinomial logistic regression was employed to explain the factors influencing farmers’ reaction towards a strong increase in water price. The results show that under increased water price less than half of the interviewed farmers would opt for decisions that lead to improved water use efficiency. Moreover, the price increase might lead to a further expansion of groundwater exploitation in the region. Fruit farmers, as well as farmers with less land and less cash income are reluctant to adopt advanced irrigation technology or improve their crop production in reaction to increased water price. It was furthermore revealed that the experience of slight water shortage in the past created awareness by farmers to use water more wisely. It is concluded that the sole increase of water price is not a viable option; an integrated approach is necessary, in which creation of awareness and improving agronomic skills of farmers play a key role to overcome the tight water situation and realize a more efficient use of water.

Comparison of energy consumption and economic performance of organic and conventional soybean production — A case study from Jilin Province, China

Abstract Modern agriculture heavily depends on energy consumption, especially fossil energy, but intensive energy input increases the production cost for producers and results in environmental pollution. Organic agricultural production is considered a more sustainable system, but there is lack of scientific research on the energy consumption between organic and conventional systems in China. The analysis and comparison of energy use between the two systems would help decision-makers to establish economic, effective and efficient agricultural production. Thus, the objectives of the present study are to analyze energy inputs, outputs, energy efficiency, and economic benefits between organic and conventional soybean (Glycine max (L.) Merrill) production. A total of 24 organic farmers and 24 conventional farmers in Jilin Province, China, were chosen for investigation in 2010 production year. Total energy input was 71.55 GJ ha−1 and total energy output was 96.18 GJ ha−1 in the organic system, resulting in an energy efficiency (output/input) of 1.34. Total energy input was 9.37 GJ ha−1 and total energy output was 113.4 GJ ha−1 in the conventional system, resulting in the energy efficiency of 12.1. The huge discrepancy in energy inputs and respective efficiencies lies in the several times higher nutrient inputs in the organic compared to the conventional production system. Finally, the production costs ha−1 were 33% higher, and the net income ha−1 25% lower in the organic compared to the conventional soybean production system. It is recommended to improve fertilizer management in organic production to improve its energetic and economic performance.

Effects of saline irrigation on soil salt accumulation and grain yield in the winter wheat-summer maize double cropping system in the low plain of North China

Abstract In the dominant winter wheat (WW)-summer maize (SM) double cropping system in the low plain located in the North China, limited access to fresh water, especially during dry season, constitutes a major obstacle to realize high crop productivity. Using the vast water resources of the saline upper aquifer for irrigation during WW jointing stage, may help to bridge the peak of dry season and relieve the tight water situation in the region. A field experiment was conducted during 2009–2012 to investigate the effects of saline irrigation during WW jointing stage on soil salt accumulation and productivity of WW and SM. The experiment treatments comprised no irrigation (T1), fresh water irrigation (T2), slightly saline water irrigation (T3: 2.8 dS m−1), and strongly saline water irrigation (T4: 8.2 dS m−1) at WW jointing stage. With regard to WW yields and aggregated annual WW-SM yields, clear benefits of saline water irrigation (T3 & T4) compared to no irrigation (T1), as well as insignificant yield losses compared to fresh water irrigation (T2) occurred in all three experiment years. However, the increased soil salinity in early SM season in consequence of saline irrigation exerted a negative effect on SM photosynthesis and final yield in two of three experiment years. To avoid the negative aftereffects of saline irrigation, sufficient fresh water irrigation during SM sowing phase (i.e., increase from 60 to 90 mm) is recommended to guarantee good growth conditions during the sensitive early growing period of SM. The risk of long-term accumulation of salts as a result of saline irrigation during the peak of dry season is considered low, due to deep leaching of salts during regularly occurring wet years, as demonstrated in the 2012 experiment year. Thus, applying saline water irrigation at jointing stage of WW and fresh water at sowing of SM is most promising to realize high yield and fresh irrigation water saving.

Assessing the Impact of Air Pollution on Grain Yield of Winter Wheat - A Case Study in the North China Plain

The major wheat production region of China the North China Plain (NCP) is seriously affected by air pollution. In this study, yield of winter wheat (Triticum aestivum L.) was analyzed with respect to the potential impact of air pollution index under conditions of optimal crop management in the NCP from 2001 to 2012. Results showed that air pollution was especially serious at the early phase of winter wheat growth significantly influencing various weather factors. However, no significant correlations were found between final grain yield and the weather factors during the early growth phase. In contrast, significant correlations were found between grain yield and total solar radiation gap, sunshine hour gap, diurnal temperature range and relative humidity during the late growing phase. To disentangle the confounding effects of various weather factors, and test the isolated effect of air pollution induced changes in incoming global solar radiation on yield under ceteris paribus conditions, crop model based scenario-analysis was conducted. The simulation results of the calibrated Agricultural Production Systems Simulator (APSIM) model indicated that a reduction in radiation by 10% might cause a yield reduction by more than 10%. Increasing incident radiation by 10% would lead to yield increases of (only) 7%, with the effects being much stronger during the late growing phase compared to the early growing phase. However, there is evidence that APSIM overestimates the effect of air pollution induced changes on radiation, as it does not consider the changes in radiative properties of solar insulation, i.e. the relative increase of diffuse over direct radiation, which may partly alleviate the negative effects of reduced total radiation by air pollution. Concluding, the present study could not detect a significantly negative effect of air pollution on wheat yields in the NCP.

A framework for standardized calculation of weather indices in Germany

Climate change has been recognized as a main driver in the increasing occurrence of extreme weather. Weather indices (WIs) are used to assess extreme weather conditions regarding its impact on crop yields. Designing WIs is challenging, since complex and dynamic crop-climate relationships have to be considered. As a consequence, geodata for WI calculations have to represent both the spatio-temporal dynamic of crop development and corresponding weather conditions. In this study, we introduce a WI design framework for Germany, which is based on public and open raster data of long-term spatio-temporal availability. The operational process chain enables the dynamic and automatic definition of relevant phenological phases for the main cultivated crops in Germany. Within the temporal bounds, WIs can be calculated for any year and test site in Germany in a reproducible and transparent manner. The workflow is demonstrated on the example of a simple cumulative rainfall index for the phenological phase shooting of winter wheat using 16 test sites and the period between 1994 and 2014. Compared to station-based approaches, the major advantage of our approach is the possibility to design spatial WIs based on raster data characterized by accuracy metrics. Raster data and WIs, which fulfill data quality standards, can contribute to an increased acceptance and farmers’ trust in WI products for crop yield modeling or weather index-based insurances (WIIs).