Winter wheat yield and soil critical phosphorus value response to yearly rainfall and P fertilization on the Loess Plateau of China
Introduction
Winter wheat (Triticum aestivum L.) dominates dryland crop production on the Loess Plateau of China, where there is a wide range of annual rainfall (from <200 mm to >900 mm). In this area, winter wheat is seeded in late September/early October and harvested in early June and is planted on more than 4.35 million hectares (2020) under rainfed farming. Therefore, wheat grain yield is strongly affected by rainfall (annual rainfall, summer-season rainfall, wheat-yearly rainfall (defined as the rainfall from June until the following May)) or stored soil water within the 300 cm soil profile at planting (Huang et al., 2003, Dai et al., 2015, Wang et al., 2016, Dai et al., 2022, Qiu et al., 2022). For example, wheat yield varies from 2246 to 6429 kg ha−1 when summer-season rainfall ranges from 95 to 475 mm (Qiu et al., 2022) and from 1603 to 3976 kg ha−1 when stored soil-water ranges from 719 to 616 mm (Huang et al., 2003). In addition, soils in this area have low organic matter, high pH, and strong phosphorus (P) fixation (Gong et al., 1999). The wheat fields in this area received a high rate of phosphorus (P) fertilizer at 53.9 kg P ha−1 yr−1, i.e., approximately 2 times the P uptake by wheat (Zhao et al., 2016, Huang et al., 2018), which resulted in a net build-up of P in the soils due to utilization by crops (10 − 25%) (Zhang et al., 2008b) and thus high available P in soils (Li et al., 2011). Although many previous researchers have focused on the relationships between crop yield and rainfall worldwide (Monti and Venturi, 2007, Ma et al., 2012, Sherrod et al., 2014, Wang et al., 2016, Zachariah et al., 2020, Bozorg-Haddad et al., 2021), there is still a lack of information on the quantitative relationship between yield and wheat-yearly rainfall in the Loess Plateau of China. Therefore, under P input conditions, understanding the links between wheat yield and wheat-yearly rainfall (especially for different rainfall patterns (dry, intermediate, and wet rainfall years)) and soil P is important for P management in dryland wheat green production.
Soil available P (e.g., Olsen P (Olsen et al., 1954), Colwell P (Colwell, 1963), Bray P (Bray and Kurtz, 1945)), together with other soil nutrients, is important for ensuring optimal wheat yields and is the basis for the recommendation of wheat P fertilization. However, if the available P in the soil is higher than a critical threshold, there is no response to the input of fresh P fertilizer and crop yields. Therefore, some researchers have proposed soil critical P values for different crops to manage P fertilization (Bai et al., 2013, Johnston et al., 2013, Poulton et al., 2013, McCaskill et al., 2020), which can improve the soil P status in P-deficient soils, limit soil P accumulation, and save phosphate resources. For soil Olsen P, the soil critical P value (at a depth of 23 cm) for wheat was 13 mg kg−1 at the Exhaustion Land site of Rothamsted based on a Mitscherlich response function and 98% of maximum yield (Poulton et al., 2013), 14.7 mg kg−1 (at a depth of 20 cm and based on a hyperbolic function and 95% of maximum yield) in Switzerland (Cadot et al., 2018), and 10.9 – 21.4 mg kg−1 (at a depth of 20 cm and based on a linear-plateau model and 90% of maximum yield) in different regions of China (Bai et al., 2013). For soil Colwell P, the proposed threshold value was 15 − 47 mg kg−1 for wheat in all of Australia (at a depth of 10 cm and based on a BFDC Interrogator function and 90% of maximum yield) (Bell et al., 2013) and 52 mg kg−1 for wheat and 59 mg kg−1 for canola in the high-rainfall zone of southern Australia (at a depth of 10 cm and based on a BFDC Interrogator function and 95% of maximum yield) (McCaskill et al., 2020). These results suggest that the soil critical P value varied in different sites and crops due to different sampling depths, extractants, choices of mathematical model and definitions of critical value (90 − 98%), agricultural systems, and crops. Meanwhile, these critical levels are in a wide range and not specific to dryland wheat, indicating that a soil critical Olsen P value for winter wheat in the Loess Plateau has not yet been determined. In this area, Huang et al. (2017) proposed a wheat P fertilization method based on soil Olsen P (P input rate (kg P ha−1) = target wheat yield (kg ha−1)÷1000 × 11 ×Pc, where Pc is a coefficient based on the testing values of soil Olsen P). If a critical Olsen P value for wheat is proposed, it will optimize this method, further helping to reduce the input of P fertilizer and save P resources.
Based on 781 pairs of datasets (with (+P) and without (−P) P fertilizer input) from field experiments over 14 years on the Loess Plateau of China, this study aimed to determine the responses of winter wheat yield to wheat-yearly rainfall and P fertilization, calculate the soil critical P value in different yearly rainfall patterns (dry, intermediate, and wet years) and then provide some suggestions to manage wheat P fertilization.
Section snippets
Study site description and experimental design
The study sites located within the province of Shaanxi, China (the center of the Loess Plateau), covered a range of climate types (semiarid and semihumid). The annual total rainfall in Shaanxi Province averages between 400 and 900 mm, while the average temperature varies from 7 °C to 16°C (http://data.cma.cn). The soil in this region is calcareous and is derived from loess parent material. The average soil properties (with a soil depth of 20 cm) in 2005 were pH 7.92, soil organic matter
Wheat grain yield and rainfall
During the experimental period, the average wheat-yearly rainfall was 543 mm (Fig. 2). For the two treatments, the wheat grain yield ranged from 858 to 9008 kg ha−1, and the average wheat grain yield was 5501 kg ha−1 (Fig. 3). Regression analysis showed that wheat grain yield in the two treatments followed a piecewise linear model with wheat-yearly rainfall (Fig. 3), with a threshold value of wheat-yearly rainfall at 527 mm for the −P treatment and 550 mm for the +P treatment. When wheat-yearly
Effect of rainfall and P fertilization on wheat yield in drylands
In rainfed cropping systems, rainfall determines soil water and thus strongly affects crop yield (Anderson et al., 2016, Wang et al., 2016). In the present study, the wheat yield increased with increasing yearly rainfall, but when rainfall reached a threshold of 550 mm (+P treatment), no significant additional yield was gained (Fig. 3). For the different types of wheat-yearly rainfall years (dry, intermediate, and wet years), wheat yield significantly increased from dry years to
Conclusions
The 781 pairs of field experiments showed that the wheat grain yield reached a high level at a wheat-yearly rainfall of 527 – 550 mm (the threshold). The +P treatment significantly increased wheat yield only in the dry years when compared with the −P treatment. In total, uptake of P fitted a piecewise linear model with wheat-yearly rainfall, but in dry and intermediate years, P uptake had a linear relationship with the amount of yearly rainfall. The soil critical Olsen P values were highest in
Funding
This work was supported by grants from the National Key Research and Development Program of China (2021YFD1900700 and 2018YFD0200400), the National Natural Science Foundation of China (32072669), and the Science and Technology Research Program of Shaanxi Province (2022PT-06).
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
References (37)
- et al.
Optimizing nitrogen input by balancing winter wheat yield and residual nitrate-N in soil in a long-term dryland field experiment in the Loess Plateau of China
Field Crop Res
(2015) - et al.
Matching NPK fertilization to summer rainfall for improved wheat production and reduced environmental cost
Field Crop Res.
(2022) - et al.
Soil testing at harvest to enhance productivity and reduce nitrate residues in dryland wheat production
Field Crop Res
(2017) - et al.
Effect of increased fertilizer applications to wheat crop on soil-water depletion in the Loess Plateau, China
Agr. Water Manag.
(2003) - et al.
Addressing the yield gap in rainfed crops: a review
Agron. Sustain Dev.
(2016) - et al.
The critical soil P levels for crop yield, soil fertility and environmental safety in different soil types
Plant Soil
(2013) - et al.
Soil phosphorus-crop response calibration relationships and criteria for winter cereal crops grown in Australia
Crop Pasture Sci.
(2013) - et al.
Dryland farming improvement by considering the relation between rainfall variability and crop yield
Environ. Dev. Sustain
(2021) - et al.
Determination of total, organic and available forms of phosphorus in soils
Soil Sci.
(1945) - et al.
Critical plant and soil phosphorus for wheat, maize, and rapeseed after 44 years of P fertilization
Nutr. Cycl. Agroecosys
(2018)
Design method and application of formula of regional crop-based compound fertilizer
The estimation of the phosphorus fertilizer requirements of wheat in southern New South Wales by soil analysis
Aust. J. Exp. Agr.
Development of soil classification in China
Diversity of anthrosols in China
Pedosphere
Phosphorus in soil, water and sediment: an overview
Plant-available soil phosphorus. Part II: the response of arable crops to Olsen P on a sandy clay loam and a silty clay loam
Soil Use Manag.
Integrated soil and plant phosphorus management for crop and environment in China. A review
Plant Soil
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