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Sign up to take part. A Nature Research Journal. Evaluating the effects of agroclimatic constraints on winter oilseed rape WOSR yield can facilitate the development of agricultural mitigation and adaptation strategies.
In this study, we investigated the relationship between the WOSR yield and agroclimatic factors using the yield data collected from Agricultural Yearbook and field experimental sites, and the climate dataset from the meteorological stations Y-EXP - Winter Hubei province, China.
Overall, Easy Girls - Les Negresses Vertes - Acoustic Clubbing precipitation was the crucial yield-limiting agroclimatic factor, and restricted the effect of optimizing fertilization. The integrated data suggest that agricultural strategies of mitigation and adaptation to climatic variability based on different agroclimatic factors are essential for improving the crop yield.
Oilseed rape, an oil Y-EXP - Winter energy crop, is Y-EXP - Winter to local climatic conditions because of its lengthy growth period and overwintering ability.
In the case of China, WOSR encountered not only temporal yield stagnation from to but Y-EXP - Winter spatial yield variability at provincial level 89. Optimum fertilization has contributed greatly to WOSR yield 1011but inadequate and excessive fertilization is common in Yangtze River Basin Identifying the agroclimatic constraints under climatic variability can help to explain the reasons for these yield issues.
The coincidence of variations in yield and climate was frequent for seed producing crops 1. A series of agroclimatic indices can be used to analyze the interactions between crop growth and climate variability, such as the decrease in the rice yield with the increase in the minimum temperature at the International Y-EXP - Winter Research Institute Farm 13the positive effects of a moderate decline in precipitation on wheat production 14and the influence Y-EXP - Winter extreme temperatures on rice yield in southern China In addition, analytical methods involving Y-EXP - Winter variables were adopted to identify site-specific yield-limiting factors 1617 Several studies have reported oilseed rape growth and yield responses to climatic parameters, and they have provided the biophysical basis of these factors 1192021 To provide insight into the relationship between the spatial yield variability and the regional climatic characteristics, scientific observations about the agroclimatic constraints on WOSR yield are essential.
The objectives of this paper were to i develop agroclimatic Y-EXP - Winter representing the effects on rainfed WOSR growth and extract the dominant agroclimatic factors, ii identify the regional agroclimatic limiting factors and quantify yield losses, and iii estimate yield gaps attributed to the limiting factors and evaluate yield gap mitigation.
The correlation Y-EXP - Winter matrix for the twelve agroclimatic indices is shown in Fig. Clearly, there were some high positive and negative correlations present. Two principal components PC were extracted, and the cumulative variance was PC1 and PC2 described There were five parts in the factor loading distribution in the first, second and fourth quadrants Fig.
In the fourth quadrant, precipitation P was chosen from precipitation at a later stage LP and minimum Y-EXP - Winter monthly temperature MT min for its higher correlation coefficient and acceptability. Additionally, precipitation at an earlier stage EP was chosen as a high loading factor for PC2. Correlation coefficient matrix A of the meteorological factors and loading distribution B in an extracted principal component analysis.
Boundary regression lines were determined by the upper boundary points for the five factors Fig. The optimum values and ranges of the dominant agroclimatic factors could be calculated on the basis Rockulator - Westworld - Beatbox Rock N Roll the boundary lines.
It is worth noting that the optimum precipitation range started at mm, at which the actual yield was the maximum. The actual yield was significantly lower than the predicted yield at a precipitation quantity of less than at mm, below which crop drought may occur.
Relationship between the winter oilseed rape yield and the dominant agroclimatic factors. The most widespread of the limiting factor across the region was AT-0, which accounted for Secondly, the limiting factor P accounted for The spatial distribution of OWD Spatial distribution A and proportion B of yield-limiting agroclimatic factors, Fruity - TerraHertz - First Smoke the attainable yield as predicted by the multivariate model.
These results indicate that the limiting factor of the temperature accumulation appeared to affect the yield within a large area, but led to a small yield loss, while precipitation at an earlier stage generally from September to November appeared to affect the yield within a small area, but resulted in a large yield loss. The two yield benchmarks for different yield-limiting agroclimatic factors were obtained by overlaying their spatial distribution maps.
Coincidentally, the highest values of Y farm and Y exp were both observed in the limiting factor of AT-0, and their lowest values were Y-EXP - Winter observed in the limiting Y-EXP - Winter of P Fig. Yield gaps for different yield-limiting agroclimatic factors.
The size of pie chart represents the Y attthe pale gray part on the left represents the Y farmthe two dark gray parts on the right represent the YG farmand the YG expand the percentage beside the pie chart represents the NYG exp.
To assess the contribution Night By Night - Chromeo - Business Casual optimum fertilization to narrowing the yield gap, NY exp was calculated using equation 5 and the results are shown in Fig.
The results indicate that precipitation was the most significant factor in the yield-limiting agroclimatic factors. The effect of the limiting factor of EP on yield was weaken under the optimum fertilization.
The boundary line approach was appropriate for the analysis of agroclimatic data in the subtropical monsoon region Fig. Our findings showed that precipitation was the most important agroclimatic constraint, and the optimum range for seasonal WOSR was from to mm Fig. The high correlation between precipitation and precipitation during the later stage Fig.
In this case, irrigation was generally not needed, but drainage was indeed necessary for WOSR, which is consistent with the perceptions of local farmers. Post-anthesis growth is important for the growth of pods and seed filling 27and waterlogging could reduce yields by restricting the seed number or weight as reported in wheat In contrast, the precipitation during the early stage should receive due attention because early drought has been considered as a key limiting factor in crop production Water deficit could decrease the germination rate and prolong germination time, leading to the reduction of root mass and leaf area in vegetative growth Farmers usually changed the sowing time or selected optimum cultivars to adapt to the variable temperature.
The low temperature affected seed germination, leaf emergence and generative development Vernalization was required for the vegetative stage of winter crops during the winter, and a warming period in the spring maintained the regrowth 20 A high negative correlation was shown between the sunshine hours and precipitation at the early stage Fig.
During the analysis of yield-limiting factors, the interactions between the agroclimatic factors and the diseases, pests and weeds caused by climate variability cannot be ignored.
For example, the interactions between rainfall and weed management in cassava production 31and the pests and soil-related factors in banana production 25 show their importance. The leaf number and dry matter accumulation were reduced by the low temperature and overcast weather that is common Y-EXP - Winter the winter in China, and root growth was hindered by early water Y-EXP - Winter and cool temperatures during WOSR production.
The yield gap concept in this paper was different from that of Lobell et al. In this paper, we did not evaluate the potential yield of WOSR 4but the attainable yield instead. Optimum fertilization could save a significant yield loss in the Yangtze River Basin of China 1011but adjusting management practices according to different weather conditions is more important for narrowing the Y-EXP - Winter gap.
The selection of agroclimatic indices and the dominant factors were sometimes subjective, but they were consistent with expectation and experience. In future studies, agroclimatic indices can be more detailed with every growth period. In this study, we did not consider the influence of regional orography since WOSR was generally planted at a low altitude in Hubei province. We believe that these results are consistent with those of other similar climatological regions, and the analytical method is applicable to other climate zones.
This paper has identified the agroclimatic limiting factors and quantified the agroclimatic-induced yield gap for WOSR in a subtropical monsoon climate.
Although the accumulation temperature affected the WOSR yield over a wide area, the precipitation appeared to be the most important agroclimatic constraint in the region. Optimum fertilization effectively narrowed the actual yield gap, especially under the limit of precipitation at an earlier stage, but its efficiency was restricted significantly Y-EXP - Winter the precipitation constraint.
The agroclimatic constraints and yield gaps presented in this study provided a basis for the development of mitigation and adaptation measures to respond to climatic variability in combination with agricultural strategies. This study was conducted in Hubei province Fig. The planting area This province has a subtropical monsoon climate, with an average annual temperature of The average temperature and total precipitation during the WOSR growing season generally from September to May of the following year were WOSR was generally rotated with rice under a double cropping system.
Distribution of meteorological stations, experimental sites and grid points for winter oilseed rape in Hubei province. Daily climate variables e. The experimental yield database were obtained from to from field fertilization experiments conducted by the local agronomists.
The yield data of optimum fertilization treatment was chosen to represent the experimental yield Y exp. The growth period was approximately days, generally from 10 September to 15 May the following year. The indicators covered the entire WOSR growing period, including germination, seedling formation, stem elongation, flowering, podding and maturation stages.
The LHomme À Tête De Chou - Gainsbourg* - LHomme À Tête De Chou, precipitation, and sunshine hours were calculated for the average of the whole growing cycle. The minimum mean monthly temperature was the average temperature of the coldest month which generally occurred in January. Precipitation at the earlier Y-EXP - Winter and later stage Dedication To All B-Boys - Schoolly D - The Collection calculated from sowing to the beginning of overwintering and from the beginning of flowering to the harvest, respectively.
Spatial interpolation, including agroclimatic indicators and yield benchmarks, was performed by the inverse distance weighted IDW method using ArcGIS version 9.
A spatial vector database consisting of 2, grid points, including 12 agroclimatic indices and WOSR yield indices, was presented Y-EXP - Winter the flow chart When Beauty Dies - Overcome - When Beauty Dies. Therefore, the grid points the combined meteorological data and yield data were used in the following analysis.
Construction process for the spatial vector database. The color of the circle represent the value of the indicator. In order to select the dominant factors from the twelve agroclimatic indices, principal component analysis PCA was adopted. The PCA was used to minimize the dimensionality of Y-EXP - Winter and identify new and important underlying variables.
The dominant agroclimatic factors were selected by considering their higher factor loading in PCs as the best representative of the system. In addition, the correlation matrix and flexible norms were used on an auxiliary basis 39 for Mobile Rock - Trio Ciclos - Mobiles Vol. 1 dominant factor selection. For each dataset related to the dominant agroclimatic factor x-axis and Y exp y-axisupper boundary points i.
The maximum yields showed an increasing tendency first and then a decrease. Hence, the quadratic model was fitted through the upper boundary points as follows:. To evaluate the yield gaps by comparison with Y atttwo yield gaps based on different yield benchmarks were defined: YG farm and Y-EXP - Winter expwhich were calculated using equation 3 and 4respectively. Then, the contribution of optimum fertilization to narrow the yield gap NY exp was calculated using equation 5.