scholarly journals Spatial variations in crop growing seasons pivotal to reproduce global fluctuations in maize and wheat yields

2018 ◽  
Vol 4 (11) ◽  
pp. eaat4517 ◽  
Author(s):  
Jonas Jägermeyr ◽  
Katja Frieler

Testing our understanding of crop yield responses to weather fluctuations at global scale is notoriously hampered by limited information about underlying management conditions, such as cultivar selection or fertilizer application. Here, we demonstrate that accounting for observed spatial variations in growing seasons increases the variance in reported national maize and wheat yield anomalies that can be explained by process-based model simulations from 34 to 58% and 47 to 54% across the 10 most weather-sensitive main producers, respectively. For maize, the increase in explanatory power is similar to the increase achieved by accounting for water stress, as compared to simulations assuming perfect water supply in both rainfed and irrigated agriculture. Representing water availability constraints in irrigation is of second-order importance. We improve the model’s explanatory power by better representing crops’ exposure to observed weather conditions, without modifying the weather response itself. This growing season adjustment now allows for a close reproduction of heat wave and drought impacts on crop yields.

2019 ◽  
Vol 56 (2) ◽  
pp. 263-279 ◽  
Author(s):  
Marzena Iwańska ◽  
Michał Stępień

SummaryDrought reduces crop yields not only in areas of arid climate. The impact of droughts depends on the crop growth stage and soil properties. The frequency of droughts will increase due to climate change. It is important to determine the environmental variables that have the strongest effect on wheat yields in dry years. The effect of soil and weather on wheat yield was evaluated in 2018, which was considered a very dry year in Europe. The winter wheat yield data from 19 trial locations of the Research Center of Cultivar Testing (COBORU), Poland, were used. Soil data from the trial locations, mean air temperature (T) and precipitation (P) were considered as environmental factors, as well as the climatic water balance (CWB). The hydrothermal coefficient (HTC), which is based on P and T, was also used. The effect of these factors on winter wheat yield was related to the weather conditions at particular growth stages. The soil had a greater effect than the weather conditions. CWB, P, T and HTC showed a clear relationship with winter wheat yield. Soil data and HTC are the factors most recommended for models predicting crop yields. In the selection of drought-tolerant genotypes, the plants should be subjected to stress especially during the heading and grain filling growth stages.


2016 ◽  
Vol 24 (2) ◽  
Author(s):  
V. Beliaev ◽  
T. Meinel ◽  
L. Grunwald ◽  
G. Schmidt ◽  
A. A. Bondarovich ◽  
...  

This article presents the results of crop yield in areas with different technologies of cultivation based on the network of automatic stations that provide data on climatic and soil-hydrological monitoring in the dry steppe during the vegetation period of May–September 2013–2016 . These data  on regional ecological and climatic parameters are of great interest to the ecologists, plant physiologists, and farmers working in the Kulunda Plain (Altai Territory). We compared the following options for cropping technologies: the modern system, which is the "no-till", technology without autumn tillage;the intensive technology of deep autumn tillage by plough PG-3-5 at a depth of 22–24 cm. Cultivation of crops was carried out using the following scheme of crop rotation: the modern system: 1–2–3–4 (wheat – peas – wheat – rape); the intensive system: 5/6 – 7/8 – 9/10 (fallow – wheat – wheat). We believe that the use of modern technology in these conditions is better due to exchange between the different layers of soil. When  the ordinary Soviet system , the so-called "plow sole" , was used , at a depth of 24 cm , we observed that this creates a water conductivity barrier that seems to preclude the possibility of lifting water from the lower horizons. Results of the study of infiltration of soil moisture at the depth of 30 and 60 cm  have shown in some years the advantages of the modern technology over the ordinary Soviet system: in the version with the use of modern technology we can trace better exchange between the various horizons and , probably,  moisture replenishment from the lower horizons. Differences in individual observation periods are comparatively large due to the redistribution of soil moisture, depending on the weather conditions, the crops used in the crop rotations, and cultivation techniques. Moreover, the average moisture reserves within the one meter layer did not show any significant differences during the growing seasons of 2013–2016 . In terms of soil moisture usage and productive grain yield according to the four year experiment, the application of the modern technology with crop rotation "wheat – rape – wheat – peas" was more effective than the ordinary Soviet system with crop rotation "wheat – fallow – wheat – wheat". The four-year observation period is clearly insufficient to identify the advantages of the modern system, as during this time it is impossible to significantly improve soil quality indicators, which will continue to determine its water-retaining properties and moisture accumulation.


2021 ◽  
Vol 9 ◽  
Author(s):  
J. H. Mejias ◽  
F. Salazar ◽  
L. Pérez Amaro ◽  
S. Hube ◽  
M. Rodriguez ◽  
...  

Nitrogen (N) is the most critical element limiting agricultural production at a global scale. Despite many efforts, the N use efficiency (NUE) in agriculture remains in a range of less than 50%. Reaching targeted crop yields has resulted in N overuse, which is an economic and environmental concern worldwide. The continuous exploration of innovative solutions has led to the synthesis of novel nanomaterials, resulting in a powerful tool for the development of new technological products. Nanofertilizers are one of the most promising engineered materials that are being tested, either for soil or foliar applications. Encouraging results have been obtained using nanofertilizers in different plant species, however, limited information has been reported about its use in grasslands. Commonly, N is applied to grassland soils as granular fertilizers, which may result in significant losses via surface runoff or leaching, ammonia (NH3) volatilization and N oxides (N2O, NO, NOx) emissions. Nitrogen nanofertilizers are expected to increase NUE by improving the effectiveness of N delivery to plants and reducing N losses to the environment. Information on the efficiency of the use of N nanofertilizers in grasslands species is scarce and the application strategies that can be used to avoid N losses are poorly understood. New scenarios of increasing economic and environmental constraints may represent an opportunity for N nanofertilizers application in grasslands. This article reviews its potential use as an innovative approach to improve NUE and reduce N losses to the wider environment, analyzing potential shortcomings and future considerations for animal food chains.


2021 ◽  
pp. 1-14
Author(s):  
Jodie A. Crose ◽  
Misha R. Manuchehri ◽  
Todd A. Baughman

Abstract Three herbicide premixes have recently been introduced for weed control in wheat. These include: halauxifen + florasulam, thifensulfuron + fluroxypyr, and bromoxynil + bicyclopyrone. The objective of this study was to evaluate these herbicides along with older products for their control of smallseed falseflax in winter wheat in Oklahoma. Studies took place during the 2017, 2018, and 2020 winter wheat growing seasons. Weed control was visually estimated every two weeks throughout the growing season and wheat yield was collected in all three years. Smallseed falseflax size was approximately six cm in diameter at time of application in all years. Control ranged from 96 to 99% following all treatments with the exception of bicyclopyrone + bromoxynil and dicamba alone, which controlled falseflax 90%. All treatments containing an acetolactate synthase (ALS)-inhibiting herbicide achieved adequate control; therefore, resistance is not suspected in this population. Halauxifen + florasulam and thifensulfuron + fluroxypyr effectively controlled smallseed falseflax similarly to other standards recommended for broadleaf weed control in wheat in Oklahoma. Rotational use of these products allows producers flexibility in controlling smallseed falseflax and reduces the potential for development of herbicide resistance in this species.


Author(s):  
Mireia Fontanet ◽  
Daniel Fernàndez-Garcia ◽  
Gema Rodrigo ◽  
Francesc Ferrer ◽  
Josep Maria Villar

AbstractIn the context of growing evidence of climate change and the fact that agriculture uses about 70% of all the water available for irrigation in semi-arid areas, there is an increasing probability of water scarcity scenarios. Water irrigation optimization is, therefore, one of the main goals of researchers and stakeholders involved in irrigated agriculture. Irrigation scheduling is often conducted based on simple water requirement calculations without accounting for the strong link between water movement in the root zone, soil–water–crop productivity and irrigation expenses. In this work, we present a combined simulation and optimization framework aimed at estimating irrigation parameters that maximize the crop net margin. The simulation component couples the movement of water in a variably saturated porous media driven by irrigation with crop water uptake and crop yields. The optimization component assures maximum gain with minimum cost of crop production during a growing season. An application of the method demonstrates that an optimal solution exists and substantially differs from traditional methods. In contrast to traditional methods, results show that the optimal irrigation scheduling solution prevents water logging and provides a more constant value of water content during the entire growing season within the root zone. As a result, in this case, the crop net margin cost exhibits a substantial increase with respect to the traditional method. The optimal irrigation scheduling solution is also shown to strongly depend on the particular soil hydraulic properties of the given field site.


2019 ◽  
Vol 70 (3) ◽  
pp. 234
Author(s):  
Xiaojin Zou ◽  
Zhanxiang Sun ◽  
Ning Yang ◽  
Lizhen Zhang ◽  
Wentao Sun ◽  
...  

Intercropping is commonly practiced worldwide because of its benefits to plant productivity and resource-use efficiency. Belowground interactions in these species-diverse agro-ecosystems can greatly contribute to enhancing crop yields; however, our understanding remains quite limited of how plant roots might interact to influence crop biomass, photosynthetic rates, and the regulation of different proteins involved in CO2 fixation and photosynthesis. We address this research gap by using a pot experiment that included three root-barrier treatments with full, partial and no root interactions between foxtail millet (Setaria italica (L.) P.Beauv.) and peanut (Arachis hypogaea L.) across two growing seasons. Biomass of millet and peanut plants in the treatment with full root interaction was 3.4 and 3.0 times higher, respectively, than in the treatment with no root interaction. Net photosynthetic rates also significantly increased by 112–127% and 275–306% in millet and peanut, respectively, with full root interaction compared with no root interaction. Root interactions (without barriers) contributed to the upregulation of key proteins in millet plants (i.e. ribulose 1,5-biphosphate carboxylase; chloroplast β-carbonic anhydrase; phosphoglucomutase, cytoplasmic 2; and phosphoenolpyruvate carboxylase) and in peanut plants (i.e. ribulose 1,5-biphosphate carboxylase; glyceraldehyde-3-phosphate dehydrogenase; and phosphoglycerate kinase). Our results provide experimental evidence of a molecular basis that interspecific facilitation driven by positive root interactions can contribute to enhancing plant productivity and photosynthesis.


1996 ◽  
Vol 36 (5) ◽  
pp. 555
Author(s):  
ID Black ◽  
CB Dyson ◽  
AR Fischle

In 11 experiments over 6 seasons the herbicide sethoxydim was applied to Machete, Spear and Blade wheat cultivars in the absence or near absence of weeds (10 sites) or where the weeds were controlled by selective herbicides (1 site), in the cropping area north of Adelaide, South Australia. The rates applied included 9-47 g a.i./ha at the 2-3 leaf growth stage and 9-74 g a.i./ha at early tillering. Except for the very long growing season of 1992, there was a highly significant positive linear correlation between the number of degree days in the growing season at each experimental site and relative mean yield increase of these sethoxydim treatments. Yield increases ranged from nil in growing seasons of about 1000 degree days to 32% in a growing season of 1480 degree days, with a median of 8% over the experiments.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jindrich Spicka ◽  
Jiri Hnilica

The paper deals with weather derivatives as the potentially effective risk management tool for agricultural enterprises seeking to mitigate their income exposure to variations in weather conditions. Design and valuation of the weather derivatives is an interdisciplinary approach covering agrometeorology, statistics, mathematical modeling, and financial and risk management. This paper first offers an overview of data sources and then methods of design and valuation of weather derivatives at the regional level. The accompanied case study focuses on cultivation of cereals (wheat and barley) in the Czech Republic. However, its generalizability is straightforward. The analysis of key growing phases of cereals is based on regression analysis using weather indices as the independent variables and crop yields as dependent variables. With the bootstrap tool, the burn analysis is considered as useful tool for estimating uncertainty about the payoff, option price, and statistics of probability distribution of revenues. The results show that the spatial and production basis risks reduce the efficiency of the weather derivatives. Finally, the potential for expansion of weather derivatives remains in the low income countries of Africa and Asia with systemic weather risk.


2021 ◽  
Vol 12 (3) ◽  
pp. 642
Author(s):  
Jacek RÓŻKOWSKI ◽  
Mariusz RZĘTAŁA

The functioning of Uzbekistan’s economy is closely linked to the water resources of its huge cross-border rivers: the Amu Darya and the Syr Darya, as well as to the groundwater present within their basins. Both natural lakes and artificial reservoirs (e.g. the Aydar-Arnasay system of lakes, the Kayrakkum Reservoir, the Chardarya Reservoir) are present there, which retain significant amounts of water, and large canals with lengths of up to several hundred kilometres which involve complex hydraulic structures are used for irrigation purposes. All these are components of a water management system which needs optimisation; as much as 80% of agricultural land is irrigated, with 70% of the water being lost due to inefficient irrigation systems. The consequence of this allocation of river flows and the overuse of water in irrigation systems has been the disappearance of the Aral Sea (1960 year – 68,900 km2, 2017 year – 8,600 km2) and the inflow of water into the Sarygamysh Lake as well as the reduction of Uzbekistan’s groundwater resources by about 40%. The intensive development of irrigated agriculture is associated with changes in surface and groundwater quality caused, inter alia, by the increased use of chemicals in agriculture and the discharge of collector-drainage waters into river systems as well as their reuse. The extent of environmental degradation in some areas (especially in the Aral Sea region) is unique on a global scale. The origins of Uzbekistan’s other hydrological tourist attractions are related to attempts to ensure the availability of water for both human consumption and industrial use under conditions of water scarcity in the country’s arid and semi-arid climates. Not just the spectacular watercourses and water bodies present there (e.g. rivers, lakes, canals), but also small water retention facilities and minor infrastructure elements (e.g. wells, springs and retention basins, canals, ditches and flow control structures) are of potential tourist importance.


2017 ◽  
Vol 5 (1) ◽  
pp. 42-50
Author(s):  
Nabin Rawal ◽  
Rajan Ghimire ◽  
Devraj Chalise

Balanced nutrient supply is important for the sustainable crop production. We evaluated the effects of nutrient management practices on soil properties and crop yields in rice (Oryza sativa L.) - rice - wheat (Triticum aestivum L.) system in a long-term experiment established at National Wheat Research Program (NWRP), Bhairahawa, Nepal. The experiment was designed as a randomized complete block experiment with nine treatments and three replications. Treatments were applied as: T1- no nutrients added, T2- N added; T3- N and P added; T4- N and K added; T5- NPK added at recommended rate for all crops. Similarly, T6- only N added in rice and NPK in wheat at recommended rate; T7- half N; T8- half NP of recommended rate for both crops; and T9- farmyard manure (FYM) @10 Mg ha-1 for all crops in rotation. Results of the study revealed that rice and wheat yields were significantly greater under FYM than all other treatments. Treatments that did not receive P (T2, T3, T7, T8) and K (T2, T4) had considerably low wheat yield than treatments that received NPK (T5) and FYM (T9). The FYM lowered soil pH and improved soil organic matter (SOM), total nitrogen (TN), available phosphorus (P), and exchangeable potassium (K) contents than other treatments. Management practices that ensure nutrient supply can increase crop yield and improve soil fertility status.Int. J. Appl. Sci. Biotechnol. Vol 5(1): 42-50


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