Chinese Journal of Agrometeorology

Variation Trend and Attribution Analysis of Potential Evapotranspiration in Different Climate Regions

LIU Wen-hui, ZHANG Bao-zhong, WEI Zheng, HAN Song-jun, HAN Cong-ying, WANG Ya-qi, HAN Xin

2023, 44(07): 545-559. doi:10.3969/j.issn.1000-6362.2023.07.001

Asbtract ( 212 )

PDF (3706KB) ( 181 )

Related Articles | Metrics

Based on the daily meteorological data of 710 stations from 1970 to 2017, authors apply the Mann-Kendall test method and contribution analysis method, analyze the variation characteristics of annual ET_o (potential evapotranspiration) and its sensitive factors, further quantify the contribution of meteorological factors to ET_o variation in different climate regions. The results showed that, (1) among 710 meteorological stations, 177 stations showed a significant increase trend (0.51 to 5.55mm·y⁻¹, P<0.05), 147 stations showed a significant decrease trend (−0.65 to −5.00mm·y⁻¹, P<0.05), and 386 stations showed no-significant change trend. T and U showed an increasing trend, while RH and RN showed a decreasing trend in different climate regions. (2) The sensitivity factors of ET_o to meteorological variables were differ in climate regions, in extreme arid region, arid region and semi-arid region ET_o was most sensitive to net radiation(RN), and most sensitive factor change to relative humidity(RH) in the semi-humid region and humid region, also the sensitivity of ET_o to RH and RN increased with the increase of humidity. (3) The change trend of ET_o was influenced by the sensitivity of climate factors and the relative rate of change. The rise of ET_o in extreme arid region, arid region, semi-arid region and semi-humid region were mainly caused by the increase of T, while the decrease of ET_o was mainly caused by the decrease of U, the change of ET_o in humid region was caused by its high sensitivity to RH and RN. In summary, compared with the sensitivity coefficient, the contribution index considering the relative rate of change is more indicative of the influence of climate factors on ET_o change. This study is conducive to for scientific understanding of regional climate change and hydrological cycle response mechanism.

Characteristics of Water Footprint for Crop Production in Shaanxi Province

HE Yu-tong, XIE Li-yong, JIN Ze-qun, LI Kuo, LIU Ying, GUO Li-ping

2023, 44(07): 560-574. doi:10.3969/j.issn.1000-6362.2023.07.002

Asbtract ( 163 )

PDF (1112KB) ( 156 )

Related Articles | Metrics

The demand of crop production to water resources is huge. In order to guide the strategies on water and nitrogen management study in sustainable agriculture, it is crucial to calculate the water footprint (WF) and analyze its characteristics. Taking Shaanxi province as the research area, WFs of three types crops including cereal, vegetable and fruit crops were calculated at the prefecture city level during 2011−2020 at the per unit area and total province level. The specific WFs and compositional structure, including green water footprint (GWF), blue water footprint (BWF) and grey water footprint (RWF) of major crop production at the prefecture city level and associated characteristics, were calculated and analyzed. Based on the calculation and analysis, suggestions on reducing WF and promoting for the sustainable agriculture were proposed. In the calculation, WF theory was used based on other data including meteorological data, statistical yearbook etc. Results showed that: (1) at the provincial level, the average WF per unit production area of major crops in Shaanxi province was ranked by: apples (10498.6m³ha⁻¹), open-field vegetable (10233.6m³ha⁻¹), soybean (5451.7m³ha⁻¹), summer maize (4771.9m³ha⁻¹) and winter wheat (3357.4m³ha⁻¹), the WF at per unit area for either apples or open-field vegetable were more than twice that of food crops, and non-natural precipitation water consumption (BWF and RWF) of open-field vegetable and apple production accounts for 75.7% and 55.3% in the total three fraction WFs, respectively. (2) The WF of crop production averaged in ten-years at the province level was ranked by apple (6.91 billion m³), open field vegetable (3.77 billion m³), winter wheat (3.37 billion m³), summer maize (2.68 billion m³) and soybeans (890 million m³) in order. The irrigation water consumed by open-field vegetables was higher than that for other crops, and the water consumption from either apples or open-field vegetables production due to nitrogen fertilizer application were higher than that from other crops. The water footprint of fruits and of vegetable crops, which consumed 47% of the total WF with only 31% of the total crop harvest area in the province. It is effective to optimize the water and fertilizer management in vegetable and fruit production processes to help release the potential of agricultural water conservation in Shaanxi province. (3) At the prefecture city level, the crop planting types in different regions in Shaanxi province were different. The WF for apple production was concentrated in the region of Yan'an, Xianyang and Weinan (77.0%), open-field vegetables was mainly planted in Guanzhong and Southern Shaanxi (90.4%), summer maize and winter wheat were mainly produced in Guanzhong (84.9% and 87.1%), and soybean planting was mainly concentrated in Northern and Southern of Shaanxi (81.1%). In order to reduce the WF of crop production aims to improve the efficiency of regional water resource use in different crop concentrated production areas, specific measures appropriated to local conditions and crop characteristics should be applied, such as techniques for rainwater collection and water-saving irrigation, high-efficiency water-saving irrigation technology and water-nitrogen coupled practices, so as to achieve the goal of sustainable agricultural development for ensuring saving water saving in crop production.

Effects of Late Spring Coldness during the Anther Differentiation Period on Grain Number and Weight of Wheat Main Stem at Different Spikelet and Grain Position

CHEN Xiang, YU Min, WANG Peng-na, DAI Wen-ci, WENG Ying, CAI Hong-mei, WU Yu, XU Hui, ZHENG Bao-qiang, LI Jin-cai

2023, 44(07): 575-587. doi:10.3969/j.issn.1000-6362.2023.07.003

Asbtract ( 175 )

PDF (466KB) ( 107 )

Related Articles | Metrics

Under the condition of pot cultivation in the field, the intelligent ultra-low temperature light incubator was used to carry out a 4h·d−1 simulation experiment of late spring coldness in the anther differentiation period of two wheat varieties, Yannong 19 (YN19, strong resistance to late spring coldness) and Xinmai 26 (XM26, weak resistance to late spring coldness). Two temperature treatments of 2℃ and −2℃ were set, and the control treatment (CK) was 10℃, in order to clarify the effect of different degrees of late spring coldness on the number of grains and grain weight at different spike positions of wheat main stem. The results showed that: (1) the number of fertile grains and grain weight at different spikelet on the main stem in different treatments were changed as a quadratic curve of first increased and then decreased. (2)Late spring coldness significantly reduced the number of fertile grains at different spikelet and grain positions of wheat main stem, and the reduction amplitude increase with the increase of stress degree. Under 2℃ and −2℃ treatment, the total fertile grains of lower, middle and upper spikelets of YN19 decreased by 40.74%, 18.75%, 35.00% and 70.37%, 32.50% and 15.00% respectively, while XM26 significantly decreased 62.50%, 7.87%, 20.00% and 100%, 42.22%, 100%, respectively. (3)Mild late spring coldness stress (2℃) reduced the grain weight of wheat main stem, while severe late spring coldness stress (−2℃) increased the grain weight due to the sharp reduction of the number of grains per spike. Compared with CK, the grain weight of spikelets of YN19 decreased by 2.93% − 47.53% and XM26 by 19.72% − 49.96% under 2℃ low temperature stress treatment; the grain weight of spikelets of YN19 increased by 20.57% − 60.84% and XM26 by 1.20% − 42.78% under −2℃ low temperature treatment. (4)The dry weight of the total grains at different parts of wheat main stem spike in two varieties was lower than that of CK due to the late spring coldness. Under the stress of 2℃ and −2℃, the dry weight of total grains of the lower and middle spikelets of YN19 significantly decreased by 49.49%, 28.99% and 65.76%, 29.47%, respectively, compared with CK, and the dry weight of total grains of the upper spikelets under −2℃was significantly reduced by 23.09% compared with CK. While under the stress of 2℃ and −2℃, the dry weight of total grains of the lower, middle and upper spikelets of XM26 significantly decreased by 69.76%, 28.61%, 20.02% and 100%, 42.33%, 100%, respectively, compared with CK. To sum up, the late spring coldness had adverse effects on the number of fertile grains and grain weight at different spikelet and grain positions of wheat main stem. The damages to the wheat main stem spike position was shown as follows: the lower spikelet > the upper spikelet > the middle spikelet, and the order of damage to the wheat grain position was shown as follows: G3 (the third grain position) > G1 (the first grain position) > G2 (the second grain position). It was concluded that the effect of late spring coldness on the number of fertile grains was greater than on the grain weight, and the degree of influence increased with the aggravation of late spring coldness stress. Both the number of fertile grains and the weight of grains showed that the lower spikelets were most affected, that is, the inferior spikelets and inferior grains were more affected by the late spring coldness. The late spring coldness during the anther differentiation period mainly reduced the number of grains per spike of the upper spikelet and the lower spikelet of the main stem spike, reduced the weight of inferior grains, and finally leads to the reduction of wheat yield. By comprehensive comparison, the damage degree of YN19 was less than that of XM26, and YN19 had stronger resistance to late spring coldness. Therefore, selecting wheat varieties with strong resistance to late spring coldness is an important measure to reduce the damage of late spring coldness in wheat production.

Assessing the Sustainability of Cotton Production under Climate Change Based on the AquaCrop Model

WANG Hong-bo, LI Guo-hui, XU Xue-wen, HUANG Wei-xiong, ZHAO Ze-yi, GAO Yang, WANG Xing-peng

2023, 44(07): 588-598. doi:10.3969/j.issn.1000-6362.2023.07.004

Asbtract ( 163 )

PDF (2491KB) ( 164 )

Related Articles | Metrics

Under the condition of limited available water resources, it is increasingly important to optimize irrigation strategies and adjust sowing dates to improve sustainability and profitable production. Authors calibrated and verified the crop parameters in AquaCrop model by using soil moisture, cotton growth, biomass and yield 2017−2018, and inputting the data into the meteorological, crop, irrigation, and field management modules. The biomass and yield of cotton under mulch drip irrigation in the oasis area of southern Xinjiang from 1988 to 2017 were simulated under 30 scenarios of different irrigation (TS1: 18mm, TS2: 24mm, TS3: 30mm, TS4: 36mm, TS5: 45mm, and TS6: 54mm) and sowing dates (D1: March 23, D2: April 3, D3: April 13, D4: April 23, and D5: May 3). The stability and sustainability of cotton production for 30 consecutive years were also analyzed. The results showed that the AquaCrop model could well simulate the cotton canopy coverage, aboveground biomass, and soil moisture under different irrigation and sowing dates. The normalized root mean square error (NRMSE) was less than 20%, and the synergistic index (d) and correlation coefficient (R2) were close to 1. The AquaCrop model underestimated cotton evapotranspiration (ET) and yield (Y) with relative error (RE) of −4.5% to 1.2% and −8.6% to −6.8%, respectively. However, it proves that AquaCrop model can be used for scenario simulation. The model prediction showed that the stability and sustainability of cotton production were less affected by sowing date, but increased with the increase of irrigation quota. With the same sowing date, the cotton biomass and yield increased with the irrigation quota. Under the 495mm irrigation quota, higher irrigation water efficiency was obtained, and the cotton yield was not significantly reduced. At the same time, under the 495mm irrigation quota, if the sowing date was postponed to April 13, it could save 36.78mm of water. If early maturing cotton seeds were used for sowing on April 23, it could save 65.34mm of water. Therefore, for regions with rich water resources, early sowing can be considered to obtain high yield, while for regions with poor water resources, late sowing is an economic and effective strategy to adapt to the current and future climate change and the shortage of water resources under the combination of varieties and cultivation models.

Effects of High Temperature on Photosynthetic Characteristics and Antioxidant Enzyme Activities of Maize Leaves during Filling Stage

YU Meng-qi, LU Meng-li, ZHANG Ya-ting, CHEN Zhi-ying, LI Wen-yang

2023, 44(07): 599-610. doi:10.3969/j.issn.1000-6362.2023.07.005

Asbtract ( 245 )

PDF (513KB) ( 175 )

Related Articles | Metrics

The present study was carried out to investigate the effects of high temperature on photosynthetic fluorescence characteristics and antioxidant enzyme activities in maize ear leaves. The pot experiments were carried out at Fengyang Experimental Station of Anhui Science and Technology University June to October 2021. Two maize cultivars, "Anke 985" and "Longping 206", were chosen in this study. The average temperature of high temperature treatment was (37±2)°C during the daytime, and the high temperature duration was 30 days. The indices including contents of yield, chlorophyll relative content (SPAD), photosynthetic parameters, chlorophyll fluorescence parameters, antioxidant enzyme (CAT, SOD, POD) activity and malondialdehyde (MDA) content of maize were measured under different treatments. The results showed that compared with the control, high temperature treatment reduced significantly grain number per row, 100-grain weight, thereby reducing maize yield per plant. The chlorophyll relative content (SPAD), net photosynthetic rate (Pn) and stomatal conductance (Gs) of maize leaves significantly decreased under high temperature treatment, while intercellular carbon dioxide concentration (Ci) increased significantly, indicating that the decreased of net photosynthetic rate (Pn) was mainly affected by non-stomatal factors. High temperature treatment had significant effect on fluorescence parameters of maize. The maximum photochemical efficiency Fv/Fm, actual photochemical efficiency (ΦPSII) and photochemical quenching (qP) of maize ear leaves decreased significantly, but the non-photochemical quenching (qN) increased significantly under high temperature treatment. After high temperature treatment, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in maize significantly decreased, but the malondialdehyde (MDA) content increased significantly. In conclusion, high temperature treatment damaged the photosynthetic apparatus of maize leaves, the activity of antioxidant enzymes decreased, the degree of membrane peroxidation increased, the relative content of chlorophyll decreased, and inhibited the photosynthetic performance, which led to the accumulation of photosynthetic assimilates blocked, resulting the maize yield decreased significant.

Construction of A Tomato Growth Rate Simulation Model Based on Climate Suitability Index

GUO Shen-bo, LIU Fu-hao, WANG Di, HUANG Bo, CAO Yan-fei

2023, 44(07): 611-623. doi:10.3969/j.issn.1000-6362.2023.07.006

Asbtract ( 182 )

PDF (1024KB) ( 132 )

Related Articles | Metrics

The microclimate of the facility is an important influencing factor for tomato growth and is characterized by complex parameters and rapid changes. In order to scientifically grasp the microclimate characteristics and explore the relationship between microclimate suitability index and tomato growth rate, two experiments were conducted in 2021 using tomatoes as the test material in insulated plastic greenhouses, with ‘Provence’ as the test tomato variety for the spring crop (January 18-May 24, 2021) and ‘Baolufuqiang’as the test tomato variety for the autumn crop (August 27-December 31, 2021), both in substrate bags. Authors adopt conventional field management methods. Microclimate including temperature, relative humidity, solar radiation, CO2 concentration and vapor pressure deficit (VPD) were monitored in the facility, and tomato morphological indicators and growth rate were measured every 7 days. Authors proposed a method for calculating the microclimate suitability index for facilities using factor analysis, and constructed a tomato growth rate simulation model based on the microclimate suitability index using multiple linear regression method to simulate and verify tomato growth rate in autumn crop. The results showed that the microclimate suitability identified based on the computational method matched 75% with that based on manual empirical judgment, and the correlation between microclimate suitability and the growth amounts of fresh tomato weight (r=0.690), dry weight (r=0.623), and plant height (r=0.748) reached significant levels (P<0.05). In the simulation results of the growth rate of autumn crop, the fitting degree and accuracy of the growth rate simulation were better. The results of autumn crop tomato growth rate simulations showed good fit and accuracy, with simulated relative growth rate at seedling stage with measured values R2=0.875 and RMSE=0.048d⁻¹, and simulated absolute growth rate at flowering and fruiting stage with measured values R2=0.785 and RMSE=0.877g·d⁻¹. In summary, this study provides a new method for quantitative facility microclimate analysis, which is more comprehensive than temperature determination, and also provides a new way of thinking for the construction of tomato growth rate model.

Simulation Model of Nutrient Quality for One-season Rice in Jianghuai Regions Based on Light and Temperature Function

WANG Xue-lin, SHANG Bing-chen, ZHANG Yu-long, LIU Jun, JIANG Yue-lin

2023, 44(07): 624-632. doi:10.3969/j.issn.1000-6362.2023.07.007

Asbtract ( 141 )

PDF (553KB) ( 120 )

Related Articles | Metrics

"Fuyou 17" of one-season rice main varieties in the Jianghuai regions was used as the experimental material, and staged sowing experiments was used, and nutritional quality indicators of rice lysine, protein, amylose and fat content were systematically measured, a simulation model of rice nutrition quality based on light and temperature function was established and tested with independent experimental data. The results showed that: (1)the nutritional quality content of rice was closely related to the temperature and light conditions during the entire growth and development of rice, and the contents of lysine, protein, amylose and fat in rice were positively correlated with the cumulative light and temperature function value. (2)Cumulative light and temperature function value during grain filling period affected grain filling process and grain weight accumulation in rice, higher the cumulative light and temperature function value after flowering, the faster the grain filling process and the shorter the duration of grain weight accumulation. (3)In the process of simulating the contents of lysine, protein, amylose and fat in rice, the light and temperature function model significantly improved the prediction accuracy of rice nutritional quality compared with the traditional thermal effectiveness and photosynthesis active radiation method and growing degree days method. The results of this study can provide important reference for the evaluation of rice climate quality and the adjustment of rice optimal sowing date in Jianghuai regions.

Establishment of Freezing Injury Index of Camellia oleifera during Flowering Period

YUAN Xiao-kang, WU Ding-rong, WANG Pei-juan, WANG Qing-ling, FAN Yu-xian, HE Na

2023, 44(07): 633-641. doi:10.3969/j.issn.1000-6362.2023.07.008

Asbtract ( 227 )

PDF (462KB) ( 151 )

Related Articles | Metrics

In order to find out the freezing injury index of Camellia oleifera, a Camellia variety named “Tiecheng No. 1”was used as test material, a artificial control experiment was carried out at the Camellia oleifera base in Changde city, Hunan province in 2020 and 2021, respectively. Taking the natural state as a control, several low-temperature freezers were used to set low-temperature treatments with different intensities at −6℃ to 3℃(or −8℃ to 2℃) for 4 hours, and the Camellia oleifera branches at the flowering stage were placed in the freezers in a non-isolated way. 7 days after treatment, the morphological changes of Camellia oleifera were observed, and the rate of falling flower (fruit) and photosynthetic parameters were determined. The results showed that the morphological indicators of Camellia oleifera, falling flowers (fruit) rate and the light response parameters were clearly changed by low temperature. As the temperature decreased, the symptoms of freezing injury became more obvious, falling flowers (fruit) rate increased, while the maximum net photosynthetic rate, apparent quantum efficiency and saturation irradiation decreased. According to the symptoms of freezing damage and the response of the above physiological indicators to different low temperatures, it was determined that −2℃ was the upper limit of freezing damage of Camellia oleifera during flowering period, −6℃ was the critical temperature for significant aggravation of freezing damage, and −8℃ was the critical temperature for serious freezing damage. It was concluded that the slight freezing injury index of Camellia oleifera during flowering period was: −6℃＜daily minimum temperature≤−2℃, and the moderate freezing injury index was:−8℃＜daily minimum temperature≤−6 ℃, and the severe freezing damage was: daily minimum temperature ≤−8℃.

Table of Content