Single Cropping System Research Articles

Water supply from pearl millet by hydraulic lift can mitigate drought stress and improve productivity of rice by the close mixed planting

The authors have proposed the close mixed planting technique using mixed seedlings of two different crop species that results in close tangling of their root systems. Especially, the combination of drought-adaptive upland crops (e.g. pearl millet or sorghum) and flood-adaptive lowland crop of rice would be beneficial to overcome the drought and flood conditions and to reduce the risks of crop failure. In our previous studies, we found that upland crop yield losses by flood stress was mitigated by mix-cropped rice, owing to the oxygen gas released from the rice roots into the aqueous rhizosphere. In the present study, we conducted two experiments to assess whether mixed cropping a drought-resistant cereal, pearl millet, would improve the performance of co-growing drought-susceptible crop, rice under drought conditions. In the field experiment, some grains were obtained from the rice plants mix-cropped with pearl millet under drought condition. However, no rice matured in the single cropping system. In the model experiment using deuterium analysis, it was confirmed that water absorbed by pearl millet roots from deep soil layer was utilized by rice, suggesting that mix-cropped rice could withstand drought stress and complete grain filling using water released into the upper soil layer by hydraulic lift.

Soy moratorium impacts on soybean and deforestation dynamics in Mato Grosso, Brazil.

Previous research has established the usefulness of remotely sensed vegetation index (VI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) to characterize the spatial dynamics of agriculture in the state of Mato Grosso (MT), Brazil. With these data it has become possible to track MT agriculture, which accounts for ~85% of Brazilian Amazon soy production, across periods of several years. Annual land cover (LC) maps support investigation of the spatiotemporal dynamics of agriculture as they relate to forest cover and governance and policy efforts to lower deforestation rates. We use a unique, spatially extensive 9-year (2005–2013) ground reference dataset to classify, with approximately 80% accuracy, MODIS VI data, merging the results with carefully processed annual forest and sugarcane coverages developed by Brazil’s National Institute for Space Research to produce LC maps for MT for the 2001–2014 crop years. We apply the maps to an evaluation of forest and agricultural intensification dynamics before and after the Soy Moratorium (SoyM), a governance effort enacted in July 2006 to halt deforestation for the purpose of soy production in the Brazilian Amazon. We find the pre-SoyM deforestation rate to be more than five times the post-SoyM rate, while simultaneously observing the pre-SoyM forest-to-soy conversion rate to be more than twice the post-SoyM rate. These observations support the hypothesis that SoyM has played a role in reducing both deforestation and subsequent use for soy production. Additional analyses explore the land use tendencies of deforested areas and the conceptual framework of horizontal and vertical agricultural intensification, which distinguishes production increases attributable to cropland expansion into newly deforested areas as opposed to implementation of multi-cropping systems on existing cropland. During the 14-year study period, soy production was found to shift from predominantly single-crop systems to majority double-crop systems.

Evaluation of Double Cropping System for Sorghum Production at Fedis, Eastern Ethiopia

Mono-cropping of sorghum is usual practice by small holders in Eastern Hararghe zone which aggravates the infestation of striga in case of susceptible varieties and has risk of crop failure in most cases due to erratic and unreliable rainfall. Thus, it was important to undertake research on cropping system which can make the farmers less vulnerable to current changing climate. Thus, an experiment was done to assess the effect of double cropping on yield, and yield components of the sorghum and compare the productivity of the double cropping with the single cropping system. The study was conducted at Fedis Research station, Eastern Hararghe during cropping season of 2015 by including two sowing time the first in April and the other during July using RCBD design. The treatments consisted were twelve including two farmers’ practices (long cycle sorghum and July planting of improved sorghum varieties) and the remaining ten treatments were double cropping of common bean and mung bean each with two varieties, lablab, cowpea, buckwheat, pearl millet, sorghum and bread wheat as preceding crops and sorghum variety Gubiye as succeeding crop. Overall, the preceding crops showed highly significant (p <0.01) difference on days to 50% flowering, days to maturity, grain yield and above ground dry biomass. The earliest days to 50% flowering were buckwheat (25.67 days) followed by common bean (var. Batu) 36 days and mung beans (var. Borada and N-26) with 38 and 38.33 days respectively. The highest above ground dry biomass was obtained from lablab (var. 147) (6116 kg ha-1) while the highest economic benefit was recorded from mung bean (var. N-26)(30315 ETB ha-1). During succeeding crops days to 50% emergence, days to 50% flowering, days to maturity, plant height, panicle length, grain yield and thousand kernel weight were highly significantly(p < 0.01)affected by the preceding crop while above ground dry biomass and harvest index were significant (p < 0.05) during the study. The latest days to 50% flowering (160.67 day) and highest days to maturity (221 day), above ground dry biomass (6119 kg ha-1) and grain yield (3369 kg ha-1) were observed for the local sorghum. However, highest grain yield was obtained from local sorghum followed by common bean (var. Batu)-Gubiye, common bean (var. Awash melka)-Gubiye and mung bean (var. N-26)-Gubiye sequences with 3369, 2342, 2107 and 2094 kg ha-1, respectively. Thus mung bean (var. N-26)-Gubiye sequence can be considered as profitable cropping sequence and recommended.

Decomposition of soil organic carbon influenced by soil temperature and moisture in Andisol and Inceptisol paddy soils in a cold temperate region of Japan

Understanding the effects of temperature and moisture on soil organic carbon (SOC) dynamics is crucial to predict the cycling of C in terrestrial ecosystems under a changing climate. For single rice cropping system, there are two contrasting phases of SOC decomposition in rice paddy soils: mineralization under aerobic conditions during the off-rice season and fermentation under anaerobic conditions during the growth season. This study aimed to investigate the effects of soil temperature and moisture on SOC decomposition under the aerobic and subsequently anaerobic conditions. Two Japanese paddy soils (Andisol and Inceptisol) were firstly incubated under four temperatures (±5, 5, 15, and 25°C) and two moisture levels (60 and 100% water-filled pore space (WFPS)) under aerobic conditions for 24 weeks. Then, these samples were incubated for 4 weeks at 30°C and under anaerobic conditions. Carbon dioxide (CO2) and methane (CH4) productions were measured during the two incubation stages to monitor the SOC decomposition dynamics. The temperature sensitivity of SOC was estimated by calculation of the Q10 parameter. The total CO2 production after the 24-week aerobic incubation was significantly higher in both soils for increasing soil temperature and moisture (P < 0.01). During the subsequent anaerobic incubation, total decomposed C (sum of CO2 and CH4 productions) was significantly lower in samples that had been aerobically incubated at higher temperatures (15 and 25°C). Moreover, CH4 production was extremely low in all soil samples. Total decomposed C after the two incubation stages ranged from 256.8 to 1146.1 mg C kg−1 in the Andisol and from 301.3 to 668.8 mg C kg−1 in the Inceptisol. However, the ratios of total decomposed C to SOC ranged from 0.29 to 1.29% in the Andisol and from 2.21 to 4.91% in the Inceptisol. Both aerobic and anaerobic decompositions of SOC in two paddy soils were significantly affected by soil temperature and moisture. Maintaining optimal soil temperature and medium moisture during the off-rice season might be an appropriate agricultural management to mitigate CH4 emission in the following rice growth season. Although it is high in SOC content, Andisol has less biodegradable components compared to Inceptisol and this could be a probable reason for the distinct difference in temperature sensitivity of SOC decomposition between two paddy soils.

Differences in the impacts of nighttime warming on crop growth of rice-based cropping systems under field conditions

Abstract Great attentions have been taken to the effects of climatic warming on crop production, however, fewer were known about the actual impacts of nighttime warming under different cropping systems. Therefore, a three-year field experiment with a passive nighttime warming (PNW) facility and a one-year field experiment with free air temperature increase (FATI) facility were conducted in major Chinese rice cropping systems. Four-year field observations from different rice cropping systems all showed that nighttime warming less than 1.0 °C could shorten the length of crop pre-flowering phase period while prolonged the length of post-flowering phase period, resulting in insignificant reduction in the length of crop entire growth period. The temperature increase caused significant increments in grain yields by 16.2, 12.7 and 12.0% for late rice in the rice–rice cropping system, wheat in the rice-wheat cropping system and rice in the single rice cropping system, respectively. However, this warming declined grain yields significantly by 4.5 and 6.5% for early rice in the rice–rice cropping system and rice in the rice-wheat cropping system, respectively. Since warming-induced yield reduction was less than warming-induced increment in each cropping system, the annual yields was higher in the warmed plots than the non-warmed under all systems. Our findings can provide important references to cropping system adjustment for coping with global warming in China and other regions.

Ecological compensation for winter wheat abandonment in groundwater over-exploited areas in the North China Plain

The land fallow policy was adopted by central and local governments to encourage the abandonment of water-intensive crops, such as winter wheat, in groundwater over-exploited areas. At the same time, since the 1990s, many households in the North China Plain (NCP) have chosen to replace the winter wheat and summer maize double-cropping system with the spring maize single-cropping system. Therefore, it is crucial to identify target land parcels for winter wheat abandonment and to design reasonable and proper standards for ecological compensation prior to the implementation of the land fallow policy in the NCP. In this study, multi-level logit models were used with household survey data in order to detect determinants across land parcel, household and village levels on household cropping system decisions; the opportunity costs for winter wheat abandonment were also calculated using cost–benefit analysis. The results show that: (1) land quality and irrigation condition at parcel level are two essential elements influencing household cropping system decisions. Nearly 70% of the total area of poor land and more than 90% of the total area of unirrigated land has suffered winter wheat abandonment. Target land parcels for the land fallow policy should be those that are irrigated and of high quality. (2) There were no significant differences between net profits from spring maize and summer maize under similar farming conditions, and the opportunity cost for winter wheat abandonment should be equal to the net profit of winter wheat. (3) The primary purpose of the land fallow policy is to induce groundwater recovery and restoration as a preliminary stage. A higher level of 350 yuan/mu is recommended as subsidy for ecological compensation at this stage. Later, the primary purpose of the policy should be a transition to a balance between exploitation and supplementation of water resources, and a lower level of 280 yuan/mu is recommended as a subsidy at this stage.

Size Matters: Assessing Optimum Soil Sample Size for Fungal and Bacterial Community Structure Analyses Using High Throughput Sequencing of rRNA Gene Amplicons.

We examined the effect of different soil sample sizes obtained from an agricultural field, under a single cropping system uniform in soil properties and aboveground crop responses, on bacterial and fungal community structure and microbial diversity indices. DNA extracted from soil sample sizes of 0.25, 1, 5, and 10 g using MoBIO kits and from 10 and 100 g sizes using a bead-beating method (SARDI) were used as templates for high-throughput sequencing of 16S and 28S rRNA gene amplicons for bacteria and fungi, respectively, on the Illumina MiSeq and Roche 454 platforms. Sample size significantly affected overall bacterial and fungal community structure, replicate dispersion and the number of operational taxonomic units (OTUs) retrieved. Richness, evenness and diversity were also significantly affected. The largest diversity estimates were always associated with the 10 g MoBIO extractions with a corresponding reduction in replicate dispersion. For the fungal data, smaller MoBIO extractions identified more unclassified Eukaryota incertae sedis and unclassified glomeromycota while the SARDI method retrieved more abundant OTUs containing unclassified Pleosporales and the fungal genera Alternaria and Cercophora. Overall, these findings indicate that a 10 g soil DNA extraction is most suitable for both soil bacterial and fungal communities for retrieving optimal diversity while still capturing rarer taxa in concert with decreasing replicate variation.

Mapping paddy rice planting area in northeastern Asia with Landsat 8 images, phenology-based algorithm and Google Earth Engine.

Area and spatial distribution information of paddy rice are important for understanding of food security, water use, greenhouse gas emission, and disease transmission. Due to climatic warming and increasing food demand, paddy rice has been expanding rapidly in high latitude areas in the last decade, particularly in northeastern (NE) Asia. Current knowledge about paddy rice fields in these cold regions is limited. The phenology- and pixel-based paddy rice mapping (PPPM) algorithm, which identifies the flooding signals in the rice transplanting phase, has been effectively applied in tropical areas, but has not been tested at large scale of cold regions yet. Despite the effects from more snow/ice, paddy rice mapping in high latitude areas is assumed to be more encouraging due to less clouds, lower cropping intensity, and more observations from Landsat sidelaps. Moreover, the enhanced temporal and geographic coverage from Landsat 8 provides an opportunity to acquire phenology information and map paddy rice. This study evaluated the potential of Landsat 8 images on annual paddy rice mapping in NE Asia which was dominated by single cropping system, including Japan, North Korea, South Korea, and NE China. The cloud computing approach was used to process all the available Landsat 8 imagery in 2014 (143 path/rows, ~3290 scenes) with the Google Earth Engine (GEE) platform. The results indicated that the Landsat 8, GEE, and improved PPPM algorithm can effectively support the yearly mapping of paddy rice in NE Asia. The resultant paddy rice map has a high accuracy with the producer (user) accuracy of 73% (92%), based on the validation using very high resolution images and intensive field photos. Geographic characteristics of paddy rice distribution were analyzed from aspects of country, elevation, latitude, and climate. The resultant 30-m paddy rice map is expected to provide unprecedented details about the area, spatial distribution, and landscape pattern of paddy rice fields in NE Asia, which will contribute to food security assessment, water resource management, estimation of greenhouse gas emissions, and disease control.

Combination of low oxygen and high carbon dioxide treatmentsalters sprouting of white asparagus

Hiroaki KITAZAWA*, Naoko HASEGAWA, Masayasu NAGATA, Machiko FUKUDA, Shin-ichi WATANABE, Atsushi YAMASAKI, Atsuko URAGAMI Food Engineering Division, National Food Research Institute, NARO, Tsukuba, Japan Vegetable Production Technology Division, NARO Institute of Vegetable and Tea Science, Tsukuba, Japan Horticulture Research Division, NARO Kyushu Okinawa Agricultural Research Center, Kurume, Japan Field Crop and Horticulture Research Division, NARO Tohoku Agricultural Research Center, Morioka, Japan

Estimation of USLE crop and management factor values for crop rotation systems in China

Soil erosion on cropland is a major source of environmental problems in China ranging from the losses of a non-renewable resource and of nutrients at the source to contamination of downstream areas. Regional soil loss assessments using the Universal Soil Loss Equation (USLE) would supply a scientific basis for soil conservation planning. However, a lack of information on the cover and management (C) factor for cropland, one of the most important factors in the USLE, has limited accurate regional assessments in China due to the large number of crops grown and their complicated rotation systems. In this study, single crop soil loss ratios (SLRs) were collected and quantified for 10 primary crops from past studies or reports. The mean annual C values for 88 crop rotation systems in 12 cropping system regions were estimated based on the combined effects of single crop SLRs and the percentage of annual rainfall erosivity (R) during the corresponding periods for each system. The C values in different cropping system regions were compared and discussed. The results indicated that the SLRs of the 10 primary crops ranged from 0.15 to 0.74. The mean annual C value for all 88 crop rotation systems was 0.34, with a standard deviation of 0.12. The mean C values in the single, double and triple cropping zones were 0.37, 0.36 and 0.28, respectively, and the C value in the triple zone was significantly different from those in single and double zones. The C values of dryland crop systems exhibited significant differences in the single and triple cropping system regions but the differences in the double regions were not significant. This study is the first report of the C values of crop rotation systems in China at the national scale. It will provide necessary and practical parameters for accurately assessing regional soil losses from cropland to guide soil conservation plans and to optimize crop rotation systems.

Single and double crop systems in the Argentine Pampas: Environmental determinants of annual grain yield

New avenues are being explored to increase food production in the extensive agriculture of highly productive temperate regions. Intensifying the use of land by sequencing two crops in a season (double cropping) may enhance annual land productivity in relation to single annual crops. Single soybean (Glycine max L. Merr.) and maize (Zea maize L.) are widespread in the Argentine Pampas while wheat (Triticum aestivum L.)–soybean double crop system is the most common land-intensive cropping system. The possibility for expanding the double cropping system is large although it has received insufficient attention. The objectives of the present study were to (i) describe the association between major environmental variables and grain yield of wheat–soybean double crop, maize and soybean single crops and (ii) compare their annual grain yield over a wide range of environments as a basis to evaluate the possible contribution to productivity expected from wheat–soybean double crop compared with maize and soybean single crops. Yield data from farms widely distributed across the Argentine Pampas and meteorological information from 30 stations distributed in the region were recorded and analyzed. A five-year period of on-farm yields were obtained from 132 groups of farmers nested in 11 zones. Variables analyzed were crop grain yields, glucose equivalents grain yields, rainfall, temperature, radiation, and frost-free period. The ratio between radiation and temperature (photo-thermal quotient; PTQ) was also considered as a grain yield determinant for wheat. Mean daily temperature during crop reproductive stages was an important determinant of maximum yields for all crops as described by a boundary-function fit. The highest grain yields of maize and soybean were obtained at moderate summer temperatures (21.8–23.5°C and 21.8–23.8°C, respectively). Wheat maximum yields increased with low spring temperatures (<18.3°C), following high photo-thermal quotients during reproductive stages. In contrast, the highest yields of double crop soybean were obtained at high summer temperatures (>21.2°C), which were associated with extended frost free periods. High yields of the wheat–soybean double crop system were obtained with cool temperatures during spring combined with a relatively extended frost free period and substantial summer rainfall. On-farm yields below the boundary-function appeared associated to low rainfall scenarios, especially in double cropped soybean fields. The geographical patterns of yield for wheat–soybean double crop system tended to be similar to that of maize and soybean single crops. The most highly productive area for the three cropping systems evaluated was located in the center of the Argentine Pampas. However, wheat–soybean double crops were more productive than soybean at any site, but their yields were slightly lower than those of maize. In addition, the work helped to identify possible areas where wheat–soybean double crop system may give relative higher advantages; particularly, in some of the currently least productive areas. Since nowadays, almost 60% of the studied area is sown with single soybean, the results suggest that there is an effective possibility to have a substantial increase in on-farm productivity, while still producing soybean, simply by expanding the double crop system.

Net primary production of major plant functional types in China: Vegetation classification and ecosystem simulation

The characteristics and distribution of vegetation are essential information for understanding the structure and functioning of terrestrial ecosystems across a large region. In this study, we developed the contemporary and potential vegetation maps of China with a spatial resolution of 1 km × 1 km. The vegetation classification scheme includes 17 types of vegetation and 3 non-vegetated land cover types. For cropland, we further provide spatial information on three major cropping systems across China, i.e., single, double and triple cropping system. In addition, we further evaluate the accuracy of this classification against field survey. As a case study, we used this vegetation data set combined with other environmental factors (climate, atmospheric CO2 and nitrogen deposition) to drive the Dynamic Land Ecosystem Model (DLEM) for estimating terrestrial net primary production at both plant functional type and national levels. DLEM simulations indicate that net primary productivity (NPP) in China's terrestrial ecosystem has substantially increased by 51%, from 2.50 Pg C y−1 in the 1900s to 3.79 Pg C y−1 during the first decade of the 21st century. Among major plant functional types across China, cropland shows the largest NPP increase by nearly 3–4 fold during 1901–2010 primarily due to cropland expansion as well as increased nitrogen fertilizer use and irrigation. The NPP increase is estimated to be 480 and 692 gC m−2 y−1 for upland crops and rice fields, respectively. This vegetation distribution data set was originally developed for driving the Dynamic Land Ecosystem model (DLEM), but it can be used for other purposes such as driving hydrological and climate models.

Biofortification: Trojan horse of corporate food control?

Biofortification of staple crops is seen as Trojan horse for the acceptance of genetically engineered food and further consolidation of corporate control on food and agriculture. Public-led biofortification programmes using conventional breeding provide an entry point for corporate interests in staple food crops in the South. The focus on single-crop systems that narrowed down the dietary base is the same approach being adopted to bring back micronutrients in staple food crops.

Differences in CH4 and N2O emissions between rice nurseries in Chinese major rice cropping areas

Studies on greenhouse gas (GHG) emissions from paddy field have primarily focused on the post-transplanting period, however, recent researches raise new concerns about GHGs emission from rice nursery. In this study, CH4 and N2O fluxes were determined from different nurseries under major rice cropping systems in China. The tested nurseries included flooded nursery (FN), moist nursery (MN) and dry nursery (DN). Methane emissions from FN were significantly higher than those from MN and DN under all the rice cropping systems. When comparing with FN, MN decreased total CH4 emissions by 74.2%, 72.1% and 49.6% under the rice–upland rotation cropping system (RUR), and the double rice cropping system for the early rice (EDR) and the late rice (LDR), respectively. DN decreased CH4 emissions by 99.2%, 92.0%, 99.0% and 78.6% compared to FN under the single rice cropping system (SR), RUR, EDR and LDR, respectively. When comparing with FN, MN and DN increased N2O emissions by 58.1–134.1% and 28.2–332.7%, respectively. Ultimately, compared with FN across the cropping systems, MN and DN decreased net global warming potentials (GWPs) of CH4 and N2O by 33–68% and 43–86%, respectively. The mitigating effect of MN and DN on total GWPs varied greatly across the systems, ranging from 30.8% in the LDR to 86.5% in the SR. Chinese actual emission from rice nurseries was reduced to 956.66 × 103 t CO2 eq from the theoretical estimate of 2242.59 × 103 t CO2 eq if under the flooded nursery scenario in 2012. Taking into account the large rice nursery area (2032.52 × 103 ha) in China, the results of this study clearly indicate the importance to estimate and mitigate GHGs emission from flooded rice nursery. Being effective to reduce GHG emissions and increase rice yield, dry nursery technique is a promising candidate for climate smart rice cropping.

The Effects of Climate Change on the Planting Boundary and Potential Yield for Different Rice Cropping Systems in Southern China

Based on climate data from 254 meteorological stations, this study estimated the effects of climate change on rice planting boundaries and potential yields in the southern China during 1951–2010. The results indicated a significant northward shift and westward expansion of northern boundaries for rice planting in the southern China. Compared with the period of 1951–1980, the average temperature during rice growing season in the period of 1981–2010 increased by 0.4°C, and the northern planting boundaries for single rice cropping system (SRCS), early triple cropping rice system (ETCRS), medium triple cropping rice system (MTCRS), and late triple cropping rice system (LTCRS) moved northward by 10, 30, 52 and 66 km, respectively. In addition, compared with the period of 1951–1980, the suitable planting area for SRCS was reduced by 11% during the period of 1981–2010. However, the suitable planting areas for other rice cropping systems increased, with the increasing amplitude of 3, 8, and 10% for ETCRS, MTCRS and LTCRS, respectively. In general, the light and temperature potential productivity of rice decreased by 2.5%. Without considering the change of rice cultivars, the northern planting boundaries for different rice cropping systems showed a northward shift tendency. Climate change resulted in decrease of per unit area yield for SRCS and the annual average yields of ETCRS and LTCRS. Nevertheless, the overall rice production in the entire research area showed a decreasing trend even with the increasing trend of annual average yield for MTCRS.

Impact of the shrinking winter wheat sown area on agricultural water consumption in the Hebei Plain

This study firstly analyzed the shrinkage of winter wheat and the changes of crop- ping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, including daily temperature, precipitation, water vapor, wind speed and minimum relative humidity data from 22 meteorological stations, and then calcu- lated the water deficit and irrigation water resources required by different cropping systems, as well as the irrigation water resources conserved as a result of cropping system changes, using crop coefficient method and every ten-day effective precipitation estimation method. The results are as follows. 1) The sown areas of winter wheat in the 11 cities in the Hebei Plain all shrunk during the study period. The shrinkage rate was 16.07% and the total shrinkage area amounted to 49.62×10 4 ha. The shrinkage was most serious in the Bei- jing-Tianjin-Tangshan metropolitan agglomerate, with a shrinkage rate of 47.23%. 2) The precipitation fill rate of winter wheat was only 20%-30%, while those of spring maize and summer maize both exceeded 50%. The irrigation water resources demanded by the winter wheat-summer maize double cropping system ranged from 400 mm to 530 mm, while those demanded by the spring maize single cropping system ranged only from 160 mm to 210 mm. 3) The water resources conserved as a result of the winter wheat sown area shrinkage during the study period were about 15.96×10 8 m 3 /a, accounting for 27.85% of those provided for Beijing, Tianjin and Hebei by the first phase of the Mid-Route of the South-to-North Water Diversion Project.

The impacts of climate change on agricultural production systems in China

Climate change can bring positive and negative effects on Chinese agriculture, but negative impacts tend to dominate. The annual mean surface temperature has risen about 0.5–0.8 °C. The precipitation trends have not been identified during the past 100 years in China, although the frequency and intensity of extreme weather/climate events have increased, especially of drought. Water scarcity, more frequent and serious outbreaks of insects and diseases, and soil degradation caused by climate change have impacted agro-environmental conditions. However, temperature rise prolonged the crop growth seasons and cold damages have reduced in Northeast China. The projection of climate change indicates that the surface temperature will continue to increase with about 3.9 to 6.0 °C and precipitation is expected to increase by 9 to 11 % at the end of 21st century in China. Climate warming will provide more heat and as a consequence, the boundary of the triple-cropping system (TCS) will extend northwards by as much as 200 to 300 km, from the Yangtze River Valley to the Yellow River Basin, and the current double-cropping system (DCS) will move to the central part of China, into the current single cropping system (SCS) area which will decrease in SCS surface area of 23.1 % by 2050. Climate warming will also affect the optimum location for the cultivation of China’s main crop varieties. If no measures are taken to adapt to climate changes, compared with the potential yield in 1961–1990, yields of irrigated wheat, corn and rice are projected to decrease by 2.2–6.7 %, 0.4 %–11.9 % and 4.3–12.4 % respectively in the 2050s. Climate warming will enhance potential evaporation and reduce the availability of soil moisture, thus causing a greater need for agricultural irrigation, intensifying the conflict between water supply and demand, especially in arid and semi-arid areas of China. With adequate irrigation, the extent of the reduction in yield of China’s corn and wheat can be improved by 5 % to 15 %, and rice by 5 % or so than the potential yield in 1961–1990. Adaptive measures can reduce the agricultural loss under climate change. If effective measures are taken in a timely way, then climate change in the next 30–50 years will not have a significant influence on China’s food security.

Pollination Decline in Context—Response

Obviously nobody would argue that pollination is the only factor affecting food production, and of course other factors can limit the importance of pollination for any particular crop ([ 1 ][1]). The purpose of studies like that of Garibaldi et al. , and others from single-crop systems ([ 2 ][2]),

Impacts of cropping practices on yield-scaled greenhouse gas emissions from rice fields in China: A meta-analysis

Recently increasing studies suggest that a comprehensive assessment of cropping practices impacts on greenhouse gas (GHG) emissions at yield-scale will benefit cropping technique innovation and policy selection for higher-yield with less-emissions. In this paper, we conducted a meta-analysis to quantify the impacts of rice cropping practices on the global warming potential (GWP) of GHG emissions at yield-scale rather than area-scale in China. The results showed that the yield-scaled GWP of Chinese major rice cropping systems during rice growing season was in the order: double rice cropping system (1188.9kg CO2equiv.Mg−1)>rice-upland crop rotation system (777.0kg CO2equiv.Mg−1)>single rice cropping system (346.7kg CO2equiv.Mg−1). Nitrogen fertilization (50–300kgNha−1) significantly increased rice yield with slight increments in the GWP of CH4 and N2O emissions, resulting in significant reductions in the yield-scaled GWP. The greatest reduction occurred at the application rate of 150–200kgNha−1 by 37% as compared to the non-fertilization control. For organic amendments, biogas residue application had no significant effect on the yield-scaled GWP, while manure application and straw recycling significantly increased the yield-scaled GWP by 54% and 154%, respectively. Intermittent irrigation significantly reduced yield-scaled GWP by 59% largely because of a significant reduction in CH4 emission and a significant increment in rice yield. No-tillage showed lower CH4 emission with similar rice yield in comparison with the conventional tillage, resulting in a reduction in yield-scaled GWP by 20%. These results indicate that there is a great potential to meet the new objective of higher-yield with less-GHG emissions through innovating rice cropping technique. More efforts should be paid on the field observations of GHG emissions during non-rice growing season, so as to perform a life-cycling assessment of GHG emissions from rice fields at yield scale under different cropping systems.

A Spatial Database of Cropping System and its Characteristics to Aid Climate Change Impact Assessment Studies

Cropping system study is not only useful to understand the overall sustainability of agricultural system, but also it helps in generating many important parameters which are useful in climate change impact assessment. Considering its importance, Space Applications Centre, took up a project for mapping and characterizing major cropping systems of Indo-Gangetic Plains of India. The study area included the five states of Indo-Gangetic Plains (IGP) of India, i.e. Punjab, Haryana, Uttar Pradesh, Bihar and West Bengal. There were two aspects of the study. The first aspect included state and district level cropping system mapping using multi-date remote sensing (IRS-AWiFS and Radarsat ScanSAR) data. The second part was to characterize the cropping system using moderate spatial resolution multi-date remote sensing data (SPOT VGT NDVI) and ground survey. The remote sensing data was used to compute three cropping system performance indices (Multiple Cropping Index, Area Diversity Index and Cultivated Land Utilization Index). Ground survey was conducted using questionnaires filled up by 1,000 farmers selected from 103 villages based on the cropping systems map. Apart from ground survey, soil and water sampling and quality analysis were carried out to understand the effect of different cropping systems and their management practices. The results showed that, rice-wheat was the major cropping system of the IGP, followed by Rice-Fallow-Fallow and Maize-Wheat. Other major cropping systems of IGP included Sugarcane based, Pearl millet-Wheat, Rice-Fallow-Rice, Cotton-Wheat. The ground survey could identify 77 cropping systems, out of which 38 are rice-based systems. Out of these 77 cropping systems, there were 5 single crop systems, occupying 6.5% coverage (of all cropping system area), 56 double crop systems with 72.7% coverage, and 16 triple crop systems with 20.8% coverage. The cropping system performance analysis showed that the crop diversity was found to be highest in Haryana, while the cropping intensity was highest in Punjab state.