Potential yields, yield gaps, and optimal agronomic management practices for rice production systems in different regions of China

2019 ◽  
Vol 171 ◽  
pp. 100-112 ◽  
Author(s):  
He Zhang ◽  
Fulu Tao ◽  
Guangsheng Zhou
2016 ◽  
Vol 155 (2) ◽  
pp. 239-260 ◽  
Author(s):  
Q. JING ◽  
J. SHANG ◽  
T. HUFFMAN ◽  
B. QIAN ◽  
E. PATTEY ◽  
...  

SUMMARYMaize in Canada is grown mainly in the south-eastern part of the country. No comprehensive studies on Canadian maize yield levels have been done so far to analyse the barriers of obtaining optimal yields associated with cultivar, environmental stress and agronomic management practices. The objective of the current study was to use a modelling approach to analyse the gaps between actual and potential (determined by cultivar, solar radiation and temperature without any other stresses) maize yields in Eastern Canada. The CSM–CERES–Maize model in DSSAT v4·6 was calibrated and evaluated with measured data of seven cultivars under different nitrogen (N) rates across four sites. The model was then used to simulate grain yield levels defined as: yield potential (YP), water-limited (YW, rainfed), and water- and N-limited yields with N rates 80 kg/ha (YW, N-80N) and 160 kg/ha (YW, N-160N). The options were assessed to further increase grain yield by analysing the yield gaps related to water and N deficiencies. The CSM–CERES–Maize model simulated the grain yields in the experiments well with normalized root-mean-squared errors <0·20. The model was able to capture yield variations associated with varying N rates, cultivar, soil type and inter-annual climate variability. The seven calibrated cultivars used in the experiments were divided into three grades according to their simulated YP: low, medium and high. The simulation results for the 30-year period from 1981 to 2010 showed that the average YPwas 15 000 kg/ha for cultivars with high yield potential. The YPis generally about 6000 kg/ha greater than the actual yield (YA) at each experimental site in Eastern Canada. Two-thirds of this gap between YPand YAis probably associated with water stress, as a gap of approximately 4000 kg/ha between the YWand the YPwas simulated. This gap may be reduced through crop management, such as introducing irrigation to improve the distribution of available water during the growing season. The simulated yields indicated a gap of about 3000 and 1000 kg/ha between YWand YW,N-80N for cultivars with high YPand low YP, respectively. The gap between YWand YW,N-160N decreased to <2000 kg/ha for high Ypcultivars with little difference for the low Ypcultivars. The different yield gaps among cultivars suggest that cultivars with high YPrequire high N rates but cultivars with low YPmay need only low N rates.


Author(s):  
Reiner Wassmann

Assessing the environmental footprints of modern agriculture requires a balanced approach that sets the obviously negative effects (e.g., incidents with excessive use of inputs) against benefits stemming from increased resource use efficiencies. In the case of rice production, the regular flooding of fields comprises a distinctive feature, as compared to other crops, which directly or indirectly affects diverse impacts on the environment. In the regional context of Southeast Asia, rice production is characterized by dynamic changes in terms of crop management practices, so that environmental footprints can only be assessed from time-dependent developments rather than from a static view. The key for the Green Revolution in rice was the introduction of high-yielding varieties in combination with a sufficient water and nutrient supply as well as pest management. More recently, mechanization has evolved as a major trend in modern rice production. Mechanization has diverse environmental impacts and may also be instrumental in tackling the most drastic pollution source from rice production, namely, open field burning of straw. As modernization of rice production is imperative for future food supplies, there is scope for developing sustainable and high-yielding rice production systems by capitalizing on the positive aspects of modernization from a local to a global scale.


2020 ◽  
Vol 115 ◽  
pp. 126011
Author(s):  
Tiemen Rhebergen ◽  
Shamie Zingore ◽  
Ken E. Giller ◽  
Charles Adu Frimpong ◽  
Kwame Acheampong ◽  
...  

2020 ◽  
Author(s):  
Hao Liang ◽  
Songjuan Gao ◽  
Zhiming Qi ◽  
Kelin Hu ◽  
Junzeng Xu

While widely studied in grassland and forest ecosystems, dissolved organic nitrogen (DON), an important form of N lost through leaching, has received little attention in cropland ecosystem research. A global literature review and partial least squares path modeling (PLS-PM) were adopted to assess the quantity and composition of N leaching loss under different cropping systems, soil types, and management practices, as well as to identify the major factors controlling DON leaching. Annual total dissolved nitrogen (TDN, organic + inorganic N) leaching under different cropping systems ranged from 4.0 to 383.2 kg N ha-1. Vegetable and rice production systems showed the greatest and least TDN leaching, respectively. Across different cropping systems, DON accounted for 4.7%–34.9% of TDN in leachate. The NH_4^+ N form of N leaching is negligible in most upland cropping systems (< 2.3%), but not so in lowland rice systems. The largest ratio of DON leaching to TDN leaching was found in a rice-wheat rotation (34.9%). Cropping systems in which animal manure or plant compost was applied or lowland rice was included showed a relatively high DON leaching ratio. Accordingly, in investigating DON leaching, more attention should be focused on cropping systems with manure application or lowland rice systems. Compared to climatic conditions and soil properties, field management practices (irrigation, chemical N input, and manure amendments) proved to be the factors most strongly influencing DON leaching. This suggests that optimizing water and N management practices is the most effective way of reducing the risk of DON leaching and increasing N use efficiency, particularly for vegetable and rice production systems.


1993 ◽  
Vol 28 (3-5) ◽  
pp. 691-700 ◽  
Author(s):  
J. P. Craig ◽  
R. R. Weil

In December, 1987, the states in the Chesapeake Bay region, along with the federal government, signed an agreement which called for a 40% reduction in nitrogen and phosphorus loadings to the Bay by the year 2000. To accomplish this goal, major reductions in nutrient loadings associated with agricultural management practices were deemed necessary. The objective of this study was to determine if reducing fertilizer inputs to the NT system would result in a reduction in nitrogen contamination of groundwater. In this study, groundwater, soil, and percolate samples were collected from two cropping systems. The first system was a conventional no-till (NT) grain production system with a two-year rotation of corn/winter wheat/double crop soybean. The second system, denoted low-input sustainable agriculture (LISA), produced the same crops using a winter legume and relay-cropped soybeans into standing wheat to reduce nitrogen and herbicide inputs. Nitrate-nitrogen concentrations in groundwater were significantly lower under the LISA system. Over 80% of the NT groundwater samples had NO3-N concentrations greater than 10 mgl-1, compared to only 4% for the LISA cropping system. Significantly lower soil mineral N to a depth of 180 cm was also observed. The NT soil had nearly twice as much mineral N present in the 90-180 cm portion than the LISA cropping system.


2019 ◽  
Vol 446 (1-2) ◽  
pp. 163-177 ◽  
Author(s):  
Arlete S. Barneze ◽  
Jeanette Whitaker ◽  
Niall P. McNamara ◽  
Nicholas J. Ostle

Abstract Aims Grasslands are important agricultural production systems, where ecosystem functioning is affected by land management practices. Grass-legume mixtures are commonly cultivated to increase grassland productivity while reducing the need for nitrogen (N) fertiliser. However, little is known about the effect of this increase in productivity on greenhouse gas (GHG) emissions in grass-legume mixtures. The aim of this study was to investigate interactions between the proportion of legumes in grass-legume mixtures and N-fertiliser addition on productivity and GHG emissions. We tested the hypotheses that an increase in the relative proportion of legumes would increase plant productivity and decrease GHG emissions, and the magnitude of these effects would be reduced by N-fertiliser addition. Methods This was tested in a controlled environment mesocosm experiment with one grass and one legume species grown in mixtures in different proportions, with or without N-fertiliser. The effects on N cycling processes were assessed by measurement of above- and below-ground biomass, shoot N uptake, soil physico-chemical properties and GHG emissions. Results Above-ground productivity and shoot N uptake were greater in legume-grass mixtures compared to grass or legume monocultures, in fertilised and unfertilised soils. However, we found no effect of legume proportion on N2O emissions, total soil N or mineral-N in fertilised or unfertilised soils. Conclusions This study shows that the inclusion of legumes in grass-legume mixtures positively affected productivity, however N cycle were in the short-term unaffected and mainly affected by nitrogen fertilisation. Legumes can be used in grassland management strategies to mitigate climate change by reducing crop demand for N-fertilisers.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 777
Author(s):  
Erythrina Erythrina ◽  
Arif Anshori ◽  
Charles Y. Bora ◽  
Dina O. Dewi ◽  
Martina S. Lestari ◽  
...  

In this study, we aimed to improve rice farmers’ productivity and profitability in rainfed lowlands through appropriate crop and nutrient management by closing the rice yield gap during the dry season in the rainfed lowlands of Indonesia. The Integrated Crop Management package, involving recommended practices (RP) from the Indonesian Agency for Agricultural Research and Development (IAARD), were compared to the farmers’ current practices at ten farmer-participatory demonstration plots across ten provinces of Indonesia in 2019. The farmers’ practices (FP) usually involved using old varieties in their remaining land and following their existing fertilizer management methods. The results indicate that improved varieties and nutrient best management practices in rice production, along with water reservoir infrastructure and information access, contribute to increasing the productivity and profitability of rice farming. The mean rice yield increased significantly with RP compared with FP by 1.9 t ha–1 (ranges between 1.476 to 2.344 t ha–1), and net returns increased, after deducting the cost of fertilizers and machinery used for irrigation supplements, by USD 656 ha–1 (ranges between USD 266.1 to 867.9 ha–1) per crop cycle. This represents an exploitable yield gap of 37%. Disaggregated by the wet climate of western Indonesia and eastern Indonesia’s dry climate, the RP increased rice productivity by 1.8 and 2.0 t ha–1, with an additional net return gain per cycle of USD 600 and 712 ha–1, respectively. These results suggest that there is considerable potential to increase the rice production output from lowland rainfed rice systems by increasing cropping intensity and productivity. Here, we lay out the potential for site-specific variety and nutrient management with appropriate crop and supplemental irrigation as an ICM package, reducing the yield gap and increasing farmers’ yield and income during the dry season in Indonesia’s rainfed-prone areas.


2007 ◽  
Vol 145 (3) ◽  
pp. 223-227 ◽  
Author(s):  
M. P. REYNOLDS ◽  
P. R. HOBBS ◽  
H. J. BRAUN

Wheat is grown on 210 million ha throughout the world producing approximately 600 million tonnes of grain (10 year average; FAO 2005) and providing on average one fifth of the total calorific input of the world's population (FAO 2003). For some regions such as North Africa, Turkey and Central Asia, wheat provides half of total dietary energy intake. Of the cultivated wheat area, half is located in less developed countries where there have been steady increases in productivity since the green revolution, associated with genetic improvements in yield potential, resistance to diseases and adaptation to abiotic stresses (Reynolds & Borlaug 2006a, b) as well as better agronomic practices (Derpsch 2005). Nonetheless, challenges to wheat production are still considerable, especially in the developing world, not only because of increased demand but also because of the increased scarcity of water resources (Rosegrant 1997; WMO 1997), ever more unpredictable climates (Fischer et al. 2002), increased urbanization and loss of good quality land away from agriculture (Hobbs 2007), and decreased public sector investment in agriculture and rural affairs (Falcon & Naylor 2005). To meet demand in a sustainable way, more resources are required to breed a new generation of genetically improved cultivars as well as implement resource-conserving agronomic management practices.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 431
Author(s):  
Caroline Wentling ◽  
Felipe S. Campos ◽  
João David ◽  
Pedro Cabral

As urbanization and agriculture increase worldwide, habitats and food sources for wild pollinators are often fragmented or destroyed. As wild pollinators contribute both resilience and variety to agricultural fields, it is desirable to implement land management practices that preserve their well-being and ability to contribute to food production systems. This study evaluates continental Portugal for its change in suitability to host bee’s pollinator species (Apis mellifera) from 1990 to 2018. It uses the InVEST crop pollination modeling tool and CORINE Land Cover, as well as parameterization to produce pollinator abundance and supply maps. These are generalized to municipality boundaries to provide actionable insights to farmers and policymakers and strengthen land management practices. It finds that the potential for pollination services is growing, with averages of both pollinator abundance and supply indices improving by 8.76% across the continental territory in 28 years. The study results are validated using another pollination index derived from a study that is based on expert opinion and field sampling in a sub-region of Portugal. This method of aggregation of model results and comparison of the percent difference by administrative boundary has the potential to better inform both policymakers and farmers about the pollination potential on a local level, as well as inspire interventions for future productivity.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 184-185
Author(s):  
Caleb M Shull

Abstract Swine producers in the U.S. face a significant challenge. On top of the ever-changing market dynamics that lead to wide swings in profitability or loss, is an underlying issue of pig mortality that the industry must address. While significant improvements in total piglets born per litter have been achieved over the last 10 years, pig mortality has seen no improvement or has worsened (Figure 1). When expressed as a percentage of piglets born (excluding mummies), a total of 7.9% were recorded as stillborn and 13.4% died prior to weaning in 2019. Assuming a typical mortality range of 7–10% from weaning to harvest, a typical U.S. producer could expect to lose around 27–30% of all piglets born. In addition, the average producer had around 12% annual sow mortality (Figure 1). Litter size and post-weaning growth rate and feed efficiency will always factor heavily into research priorities due to the economic impact associated with those traits; however, the opportunity to drive value through reduction in pig losses across the production cycle is staggering. In defense of the industry, improving pig survival is not an easy task for a number of reasons. The sample size (i.e., number of pigs) required to do mortality research correctly is often a limiting factor for many production systems. Furthermore, a cross-functional approach is likely required to make significant improvements in mortality. Specifically, the relationship between genetics, health, and management practices warrant consideration. Recent collaboration across the industry to improve mortality is a positive step forward and this collaboration should continue moving forward.


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