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20 December 2024, Volume 45 Issue 12

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Immobiliaztion Effect of Arsenic in Contaminated Red Soils and Its Enzyme Activities after Application of Lanthanum-modified Biochar

XIE Jin-ni, LI Lian-fang, LV Peng, WANG Zi-han, YAN Ao, KANG Meng-qi, ZHOU Xue, YE Jing

2024, 45(12):  1391-1404.  doi:10.3969/j.issn.1000-6362.2024.12.001

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Biochar pyrolysis at high temperature with limited oxygen plays an important role in the resource utilization of agricultural waste, carbon sequestration and emission reduction, indicating the great potential of biochar for remediating contaminated environment. As a functional material for soil remediation, its ability of adsorption and fixation for heavy metals is still insufficient, which limits the large-scale promotion and application of biochar. Nowadays, it has been an increasingly important research area to enhance the adsorption and fixation capacity of biochar through modification design of engineered materials. In this study, wood chips were used as raw materials to prepare biochar (BC), and then lanthanum modified biochar (LBC) was manufactured. Aiming to remediate arsenic contaminated red soil and compare the immobilization difference, these two kinds of amendments (LBC, BC) were applied into the experimental soils separately, and the blank soil without material addition was used as control treatment. All these above treatments was cultivated for 30days under the soil moisture content with 30%, 70%, and 100% field water capacity respectively, and the corresponding remediation effects of arsenic contaminated red soil by using LBC and BC were investigated. The results were as following: (1) LBC addition was beneficial for alleviating the acidification of southern red soils. When the cultivation experiment was finished, soil pH treated by LBC was enhanced obviously and the increased pH ranged from 0.86 to 1.20 units under three kinds of soil moisture content with 30%, 70%, and 100% field water capacity. In comparison with BC treatment, the soil pH also increased by 0.09−0.44 units after LBC addtion. (2) LBC application led to the obvious immobilization effect of arsenic in red soils, and the related fixation efficiency under three kinds of soil water content was up to 54.7%−90.0% during the whole soil cultivation period, and the immobilization efficiency reached 81.0%−85.8% after 30days of cultivation. On the contrary, soil treated by BC resulted in the arsenic activation of soils with the increased percent 135.4%−895.9% compared to the control. (3) The immobilization effect of LBC on soil arsenic is mainly related to the transformation of arsenic in various speciation, especially from non-specialized adsorption forms to more stable ones such as residue forms. In the meanwhile, BC resulted in the enhancement of non-specialized adsorption arsenic and promoted the activation of soil arsenic. (4) LBC was capable of immobilizing arsenic in red soils with high efficiency, and did not obviously excert negative influence on soil enzyme activity. The application of LBC was able to improve the activity of soil urease and catalase although it led to a slight decrease in soil phosphatase and sucrase activities. It is worth mention that LBC treatment remained higher soil sucrase activities than those for BC treatments. Overall, it manifest that LBC has great potential for remediating arsenic contaminated red soil.

Effect of Transfer Methods on Measurement of Extracellular Enzyme Activities in Winter Wheat Field under Different CO₂ Concentration

BAI Jia-shao, HAN Xue, ZHANG Xin-yue, BAO Xiu-rui, XU Yin-long

2024, 45(12):  1405-1416.  doi:10.3969/j.issn.1000-6362.2024.12.002

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 The soil slurry transfer methods (e.g. transferring soil slurry when it was continuously agitating or reached standing state) for extracellular enzyme activity (EEA) measurement are still different. Whether the result of EEAs is consistent between the two transfer methods remains unclear and needs to be tested. This research aimed to estimate the impact of transfer methods on EEA under different environmental conditions. Surface soil was collected in different growth stages of winter wheat. The winter wheat field was located in a free air carbon dioxide enrichment (FACE) platform in Changping district of Beijing. The FACE platform included two CO₂ concentrations, which were ambient CO₂ concentration (420±15μmol·mol⁻¹) and elevated CO₂ concentration (550±15μmol·mol⁻¹), respectively. Seven EEAs were chosen to study the influence of different transfer methods under different CO₂ concentrations. The results showed that the EEAs were significantly higher under agitating state than standing state. It might be attributed to the fact that soil slurry under agitating state contained more soil particles, which were easily to absorb extracellular enzymes. The extent of influence of transfer methods on EEA varied among different enzymes. To be specific, the carbon (C) and phosphorus (P) acquiring enzyme activities were strongly influenced by transfer methods, showing a significant increase of 191.45% to 774.09% under agitating state compared to standing state, while the nitrogen (N) acquiring enzyme activity only showed an increase of 6.66% to 30.59% under agitating state compared to standing state. The transfer methods also led to different responses of enzyme activities to elevated CO₂. Most enzyme activities showed no response to elevated CO₂ under the agitating state. By contrast, more enzyme activities decreased significantly in response to elevated CO₂ under the standing state. Furthermore, the calculated extracellular enzymatic stoichiometry and vector characteristic both indicated that microbial resource limitation was unchanged by elevated CO₂ under agitating state. However, under the standing state elevated CO₂ reduced microbial C limitation and enhanced microbial N limitation. This study provided valid evidence that transfer methods had a distinguished impact on enzyme activities, extracellular enzyme stoichiometry, vector characteristic, and their response to elevated CO₂. Consequently, the result of microbial resource limitation under elevated CO₂ differed between the two transfer methods. Based on this, authors strongly suggest to unify the transfer method to reduce study uncertainty. 

Fertilization Effects on Highland Barley Yield in Western China Based on Meta Analysis

LI Shun, LIU Zong-qing

2024, 45(12):  1417-1425.  doi:10.3969/j.issn.1000-6362.2024.12.003

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By searching for research papers published on China National Knowledge Infrastructure (CNKI) using keywords, based on monoculture of highland barley in the field, clear experimental sites, control and experimental groups with a repetition rate of ≥2 times, and clear records of fertilization types, seeding rate, years, altitude, annual average temperature, and annual precipitation standards, the articles were screened and the required data were extracted. Finally, 47 yield data containing 415 groups of highland barley fertilization and non-fertilization treatment conditions were adopted, and the effect size of fertilization on highland barley yield were determined using Meta-analysis method. The effects of experimental locations, sowing amounts, altitude, annual average temperature, and annual precipitation on heterogeneity of effect size were also studied to explore the effects of fertilization on highland barley yield in different environments. The results showed that fertilization increased the yield of highland barley in western China by 52.20%. Single application of nitrogen fertilizer, phosphorus fertilizer, and organic fertilizer increased the yield of highland barley by 29.69%, 34.99%, and 55.27%, respectively. The combined application of nitrogen phosphorus, nitrogen potassium, phosphorus potassium, and nitrogen phosphorus potassium, as well as the application of chemical fertilizers and organic fertilizers, increased the yield of highland barley by 58.41%, 69.89%, 25.86%, 60.00%, and 63.23%, respectively. According to heterogeneity testing, there was significant heterogeneity in the yield of highland barley. Without excluding the collinearity of factors, the experimental location, seeding rate, altitude, annual average temperature, and annual precipitation accounted for 18.98%, 15.13%, 24.86%, 28.14%, and 26.31% of the overall heterogeneity, respectively. Different experimental sites correspond to different environmental conditions, and reasonable fertilization and appropriate sowing rates are beneficial for increasing yield of highland barley.

Optimization of Crop Planting Structure in Guizhou Based on the Water-Energy- Food Nexus

HAN Shun-li, ZHANG Peng-fei, LU Yuan, ZHANG Jiao-jiao, LIU Geng, DAI Yan-yan, ZHANG Lei, GUO Li-gang

2024, 45(12):  1426-1437.  doi:10.3969/j.issn.1000-6362.2024.12.004

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 The water and energy consumption characteristics of five crops (rice, corn, potato, rape and soybean) in Guizhou from 2010 to 2020 were analyzed using a water footprint and energy consumption accounting model based on relevant statistical data. Additionally, a multi-objective optimization model with constraints on water resources, energy, land, and food supply was developed to achieve optimal economic and ecological benefits, aiming to scientifically optimize the planting structure of five crops in Guizhou. The results showed: (1) there were significant differences in the water footprint and energy consumption per unit area of major crops in Guizhou during the period from 2010 to 2020. Specifically, rice, potato, soybean, corn, and rape were classified as extremely high water and energy-consuming crops, high water and energy-consuming crops, high water but medium energy-consuming crops, medium water and low energy-consuming crops, and low water and energy-consuming crops, respectively. (2) The water footprints of five crops were primarily dominated by green water consumption. Among them, rice, corn, and potato were the major contributors to the water footprint, accounting for 85% of the total. The energy consumption structure of five crops differed, with rice mainly consuming electricity, corn and potato mainly consuming chemical fertilizers, and rape and soybean primarily consuming fuel. Notably, rice and potato were the major contributors to the energy consumption, accounting for 69% of the total. (3) There were significant spatial variations in the crop planting structure in Guizhou due to differences in natural conditions. Specifically, rice was primarily distributed in the flat areas below 600m in altitude in southern Guizhou, corn was planted across the province but with varying qualities, potato was mainly cultivated in areas with altitudes ranging from 100 to 2900m, rape was primarily planted in central Guizhou, and soybean was cultivated in all regions with small differences in the proportion of each region. (4) After optimization, there was a slight decrease in the total planting area of five crops in Guizhou province. Notably, the planting area of rape and potato increased by 14000 and 146000ha respectively, resulting in their shares increasing by 0.6 and 1.6 percentage points, respectively. Conversely, the planting area of rice and corn decreased by 171000 and 386000ha, respectively, causing their shares to decrease by 0.3 and 1.5 percentage points, respectively. Following the optimization in Guizhou, there was a reduction in water footprint of 3.06 billion m³, a decrease in chemical fertilizer usage of 150 million tons, and a reduction in energy consumption of 2459000 GJ. Consequently, the ecological benefits have been significantly improved, while the economic benefits have remained stable. The optimized planting structure, based on the water-energy-food nexus, considers both economic and ecological benefits, exhibiting characteristics of low water consumption, low energy consumption, and low pollution. This further promotes the sustainable development of agriculture in Guizhou.

Variation and Relationship between Tea Tree Canopy Temperature and Atmospheric Temperature

TAO Yao, YU Yan-wen, YANG Ai-ping, WU Wen-xin , CHEN Jiao-jiao, CAI Zhe, ZHANG Xiao-fang

2024, 45(12):  1438-1449.  doi:10.3969/j.issn.1000-6362.2024.12.005

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The difference of canopy-air temperature can indirectly monitor the variation of tea tree heat and moisture. However, the time lag effect between the tea tree canopy temperature and atmospheric temperature of tea plantation will affect the monitoring effect. In order to explore the time lag effect and the variation law between canopy temperature and atmospheric temperature, the variation characteristics of tea tree canopy temperature and atmospheric temperature of tea plantation during different tea picking seasons and different weather types were analyzed based on the monitoring data of microclimate station in tea plantation and near national meteorological station in Wuyuan from March to September in 2020. The simulated models of daily average canopy temperature and atmospheric temperature of tea plantation according to different weather types were established through the linear regression method and tested to provide data support for tea meteorological service. The results showed that: (1) the diurnal variation of tea tree canopy temperature and atmospheric temperature of tea plantation showed an obviously single-peak trend during different tea picking seasons and different weather types, while the change intensity of canopy temperature was greater than that of atmospheric temperature of tea plantation, and the peak time of canopy temperature was generally about 1h earlier than that of atmospheric temperature of tea plantation. (2) The point temperature difference of tea tree canopy and atmospheric temperature of tea plantation within 24h a day were generally ranked as spring tea＞autumn tea＞summer tea, sunny days＞cloudy days＞rainy days. In general, the canopy temperature was above or near to the atmospheric temperature of tea plantation around noon, while the canopy temperature was lower than the atmospheric temperature of tea plantation at all times in rainy days. (3) From the aspects of daily average temperature, it showed that the canopy was generally lower (1-2℃) than which in the atmosphere, but the changing trend was the same. (4) All kinds of daily average temperature prediction models were approved by 0.01 level significant test, which meaned the simulation effect were good generally. What’s more, the simulation effect of the atmospheric temperature of tea plantation prediction models were better than that of canopy temperature. In addition, under different weather types, the optimal effect of the prediction models were demonstrated in rainy days, followed by sunny days, and relatively poor in cloudy days.

Effects of Formulation of Piriformospora indica Biofertilizer and Fertilization Time on Rice Growth

CHEN Jian-zhen, MU Qi-lin

2024, 45(12):  1450-1460.  doi:10.3969/j.issn.1000-6362.2024.12.006

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Using straw carrier-based Piriformospora indica biofertilizer as the experimental material, three treatments, biofertilizer solution 1 (BFS1), biofertilizer solution 2 (BFS2) and sterile water as control (CK), were set up to determine germination potential and germination rate of rice seeds. Three fertilizer treatments (BF1: 75% compound fertilizer +25% biofertilizer 1, BF2: 75% compound fertilizer +25% biofertilizer 2 and CK: 100% compound fertilizer) and two fertilization time treatments (15 days before transplanting and at transplanting) were set up to determine root morphological indices, leaf photosynthetic indices, seedling agronomic traits of rice seedling and colonization of Piriformospora indica. Results showed that germination of rice seeds were inhibited, and germination time was delayed by 1−2 days, and germination rates were significantly reduced by 8.7 percentage points and 52.0 percentage points by BFS1 and BFS2, respectively (P<0.05). Growth of rice seedlings was promoted by straw carrier-based Piriformospora indica biofertilizer, and a better effect was shown under BF2 treatment. Compared with CK, plant height, fresh weight above ground, root weight, weight per plant and length of the longest leaf were significantly increased by 34.5%, 76.0%, 47.0%, 54.7% and 53.9%, respectively, and total root length, root diameter, projected area, surface area, root volume and root tip number were significantly increased by 24.3%, 39.4%, 101.9%, 95.3%, 188.3% and 98.3%, respectively, and the content of chlorophyll b was significantly increased by 51.5% under BF2 treatment (P<0.05). Compared with fertilization at 15 days before transplanting, root diameter, projection area, root volume and number of root tips were significantly increased by 19.2%, 10.5%, 55.6% and 45.7%, respectively, and root activity, chlorophyll a content and carotenoid content were significantly increased by 27.9%, 10.7% and 16.9%, respectively, and stem length and longest leaf length of rice seedlings were significantly increased by 8.2% and 10.5% under fertilization at transplanting treatment (P<0.05). In conclusion, straw carrier-based Piriformospora indica biofertilizer solution inhibited seed germination, prolonged germination time and increased growth difference among rice seeds. The combined application of BF2 and compound fertilizer at transplanting could improve the overall quality of rice seedlings and show a better promoting effect. Combined with previous experimental results, it is suggested that the low concentration (25%−50%) of biofertilizer solution should be selected at germination stage of rice seeds, and 75% compound fertilizer and 25% biofertilizer 2 should be co-applied at transplanting. 

Effects of Warming Treatment at Flowering Stage on Mineral Elements Accumulation in Different Organs and Calyx Abscission of Fragrant Pear

NUERMAIMAITI Aimaiti, LI Xiu-xia, QIMAN Yunus, AILIJIANG Maimaiti

2024, 45(12):  1461-1470.  doi:10.3969/j.issn.1000-6362.2024.12.007

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Korla fragrant pear was used as the test material, natural (CK) treatment and warming treatments at the early flowering （T1）and full flowering（T2）stages were set up control experiments on pear trees in orchards. The mineral element content in the fruit and calyx at the beginning of fruit setting stage, abscission zone formation stage and calyx abscission stage was measured to explore the effect of temperature changes during the pear flowering period on the calyx abscission rate and fruit setting rate of Korla fragrant pear fruit, as well as its relationship with mineral element accumulation and to provide a basis for clarifying the regulation of fruit shape formation in the environment of temperature changes during the flowering period. The results showed that compared with control treatment, the calyx abscission rate was decreased with warming treatment at different flowering stages, and reached the significant level at full flowering stage treatment which decreased from 48.06% to 20.95% that was 27.11 percentage points lower than the control group, while the fruit setting rate of each treatment group had no significant difference. At the beginning of fruit setting, N，P，Zn content in fruit and calyx was increased, but K and Ca content was decreased, while Fe content was increased and Mg content decreased in fruit. During the abscission zone formation stage, the P content in the calyx of abscission zone non-formated fruit was higher than that in the calyx of abscission zone formated fruit, and the K and Mg content were lower than that, while the Fe and Mg content in the abscission zone formated fruit is higher than the abscission zone non-formated fruit. During the calyx abscission period, the N, Fe, and Zn content in the calyx persistent fruit was higher than that in the calyx abscission fruit, but the Ca and Mg content was lower than that in the calyx abscission fruit. Warming treatment at different stages of flowering would increase the accumulation levels of N, Fe, and Zn in different parts of young fruits at the beginning of fruit setting stage, which may lead to calyx persistence, but the effect on fruit setting rate was not significant. In the context of global climate change, corresponding control measures should be taken according to weather variations during the flowering period to manage the microenvironment of orchards, and reasonable fertilization should be applied to improve fruit setting and calyx abscission rate, achieving the goal of high efficiency and yield.

Two Types of El Niño Events Effects on the Occurrence of Nilaparvata Lugens (Stål) in South China

RONG Mei-yan, BAO Yun-xuan, ZENG Juan

2024, 45(12):  1471-1486.  doi:10.3969/j.issn.1000-6362.2024.12.008

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In order to explore the different effects of Central Pacific El Niño (CP) and Eastern Pacific El Niño (EP) on the occurrence of Nilaparvata lugens (Stål) in South China and the underlying climatic causes. Based on the light−trap data of N. lugens and meteorological data from 1979 to 2020, the effects of different meteorological conditions of two types of El Niño events on the occurrence of N. lugens in South China was discussed by means of nonparametric tests, correlation analysis and inverse distance weight. The results showed as follows: (1) there was a significant difference between the effects of CP events and EP events on the occurrence of N. lugens in South China, with CP events being more likely to trigger a large occurrence of N. lugens immigration in South China. (2) The occurrence degree of N. lugens in South China was significantly affected by the atmospheric temperature fields during the impact of CP events, whereas it was affected not only by the atmospheric temperature fields but also by the precipitation during an EP events. (3) The differences of atmospheric temperature fields and atmospheric circulation situation between the two types of El Niño events were the main reasons for the different occurrence degree of N. lugens in South China.

Research on Simulation Model of Tomato Fruit Growth Based on Meteorological Factors

LI Wei, LIU Jun, LIU Yang, JIANG Lan, XIE Jin-hua, WANG Xue-lin, ZHANG Yu-long

2024, 45(12):  1487-1495.  doi:10.3969/j.issn.1000-6362.2024.12.009

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 To explore the effect of greenhouse microclimate on the growth of protected tomatoes, two models were established: one for simulating the transverse diameter and another for the single fruit weight. These models incorporated accumulated radiation-heat and the rice clock model, utilizing data on the transverse diameter and single fruit weight of protected tomatoes, as well as concurrent meteorological data including illumination, temperature, and humidity from the greenhouse at Hefei Agricultural Meteorological Experiment Station for the years 2022 and 2023. The accuracy of both was verified using experimental data from 2022. Results indicated that both models effectively simulated the transverse diameter and single fruit weight of protected tomatoes, respectively. The transverse diameter model achieved a root mean square error (RMSE) of 1.03mm, a mean absolute error (MAE) of 0.84mm, and a mean relative error (MRE) of 7.5%. The single fruit weight model achieved an RMSE of 692.59mg, an MAE of 395.44mg, and MRE of 8.2%. Decision coefficients exceeded 0.98 for both models, suggesting they possess practical value and can provide a theoretical foundation for environmental regulation in protected tomato cultivation.

Effects of Straw Carrier-based Piriformospora indica Biofertilizer on Seed Germination and Seedling Growth of Rice

CHEN Jian-zhen, MU Qi-lin

2024, 45(12):  1496-1506.  doi:10.3969/j.issn.1000-6362.2024.12.010

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 In order to solve the problem that straw mulching inhibits seed germination and seedling growth, biofertilizer was made by inoculating Piriformospora indica solution on rice straw and the activity of the biofertilizer and its effect on rice seed germination and seedling growth were discussed to provide theoretical basis for the application of straw mulching and biofertilizer. In this study, two kinds of biofertilizer were made using straw and peat as carriers, and the toxicity of the two carriers on Piriformospora indica and the change of the number of viable colony forming units (CFU) during the storage period of the biofertilizer was detected to determine whether straw was a suitable carrier for Piriformspora indica. Then, two kinds of fertilization (biofertilizer as base fertilizer and seed soaking with biofertilizer extract) with three fertilizer treatments [straw treatment (ST), biofertilizer treatment (BF) and conventional fertilization as control (CK)) and five seed soaking treatments (four biofertilizer extract gradients of 25%, 50%, 75% and 100%, and sterile water as control (CK)] were set up to treat the seeds of Lvhan 1. Then, the comparative analyses of the germination indexes, agronomic traits, root morphology and physiological indices under different treatments were conducted, and the fertilization effect was evaluated, and finally the appropriate fertilization concentration and fertilization method were selected. Results showed that: (1) the number of viable CFU was significantly increased by 2.89 times and 1.89 times during 0~6 days after inoculation on straw and peat carriers, respectively (P<0.05). During the 180 days of straw carrier-based Piriformospora indica biofertilizer stored at room temperature (25℃) , the number of viable CFU of the biofertilizer showed a trend of first increased and then decreased with the extension of storage time. The number of viable CFU was significantly increased by 32.08% and 31.13% at 30th and 60th day, and significantly decreased by 61.23%, 96.60% and 98.70% at 120th, 150th and 180th day than that of the initial (P<0.05). (2) Compared with straw treatment, plant weight, stem length, root length, projection area, surface area, root activity, the contents of both chlorophyll a and chlorophyll b were significantly increased under biofertilizer treatment. (3) Rice seed germination was inhibited by biofertilizer extract, and the inhibition effect was strengthened with the increase of concentration of the extract. Biofertilizer extracts of different concentrations showed different effects, namely low concentration promoted growth and high concentration inhibited growth, on germ length, radicle length, seedling root morphological indices, stem length, longest leaf length and plant weight, and they were obviously promoted by 25% biofertilizer extract. However, germ length, root morphological indexes and plant weight were significantly reduced by 34.07%, 43.53%−63.97% and 19.51% by the original extract solution(100%), respectively (P<0.05). This study showed that combined with straw mulching, the biofertilizer made by inoculating Piriformospora indica solution on straw-carrier was a suitable rice planting strategy. Mixing compound fertilizer and Piriformospora indica biofertilizer at 3:1 and seed soaking with 25% biofertilizer extract were two fertilization methods and fertilization concentrations appropriate to both rice seed germination and seedling growth.

Risk Assessment of Late Frost Damage and Zoning of Mainly Cultivated Apple in Ningxia

MA Meng-yao, ZHANG Xiao-yu, YANG Yong-e, LIANG Xiao-juan, ZHANG Zhi-wei

2024, 45(12):  1507-1520.  doi:10.3969/j.issn.1000-6362.2024.12.011

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Flowers and fruits collected from the two major apple varieties (‘Gala’ and ‘Fuji’) grown in Ningxia during the bud, full-bloom, fruiting and young fruit setting stages were used as test material for the cryogenic treatments, and then the freezing rates of the ovaries under different cryogenic treatments were counted and analyzed. The Logistic equations established for the 20%, 50% and 80% freeze rates were set as the indicators of light, moderate and severe frost damage, respectively. The daily minimum temperature data collected in 19 meteorological stations from 1981 to 2022 were used to analyze the scope, frequency, intensity, and risk characteristics of disaster−causing factors of frost occurrence in Ningxia from the point of view of climatic disaster, by the means of mathematical statistics and spatial analysis. The classification of frost risk was completed by analyzing the difference in risk of late frost damage to apples in various regions of Ningxia, based on a combination of the vulnerability index and the exposure index of the affected apple. The results showed that the late frost damage to ‘Gala’ and ‘Fuji’ apple in Ningxia often occurred between 20 April and 10 May during the flowering and fruit setting period. The high−risk areas of late frost damage to ‘Gala’ and ‘Fuji’ apple were mainly located in the south-central areas close to the mountain ranges, among which Jingyuan, Xiji, and Longde were the highest risk areas, with a risk index of H_i＞0.3. The suitable areas for apple cultivation were mainly in Pingluo, the southeastern part of Yinchuan, the Litong district of Wuzhong, the western part of Linwu, and parts of Zhongwei city, with an exposure index of 0.7−1.0. The high risk areas for ‘Gala’ were located in the western part of Lingwu, the western part of Shapotou, and the central parts of Zhongning county in the northern Ningxia, and Xiji county and Longde county in the southern Ningxia. The high risk area for Fuji was located in the western part of Lingwu, Xiji county and most part of Longde county. Unsuitable areas for ‘Gala’ and ‘Fuji’ apple were mainly located along the Helan, Luoshan, Nanhua and Liupan mountain areas. In terms of frost resistance, Gala apple is stronger than ‘Fuji’ apple, and the resistance of ‘Gala’ apple is decreasing as the phenology evolves, since the phenological phase of ‘Gala’ is earlier than that of ‘Fuji’ apple. According to the frost damage zoning maps, ‘Gala’ is in higher risk than ‘Fuji’. The zoning results reflected the actual distribution of late frost risk for ‘Gala’ and ‘Fuji’ apple cultivated in Ningxia. The zoning map is providing a scientific baseline for the proper distribution of apply cultivation as well as for the disaster prevention and mitigation in Ningxia.

Tomato Ripeness Detection Method Based On Improved YOLOv5

LIU Yang, GONG Zhi-hong, LI Zhen-fa, LIU Tao, ZHAO Zhuo, WANG Teng-ge

2024, 45(12):  1521-1532.  doi:10.3969/j.issn.1000-6362.2024.12.012

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In order to improve the recognition accuracy of tomato fruit ripeness and to realize online nondestructive automatic detection in tomato planting chain, this study proposes a tomato ripeness detection method based on improved YOLOv5. In the field of agriculture, accurate identification of tomato ripeness is very important, which can help agricultural production to rationalize labor arrangements and timely harvesting, thus improving the yield and quality of agricultural products. Traditional target detection algorithms face some challenges in tomato ripeness recognition, such as misidentification and missed detection, due to factors such as vines and leaf shading between tomato fruits and light interference. Therefore, this study had carried out a series of optimizations of YOLOv5 to address these problems in order to improve the accuracy and robustness of the algorithm. In the first place, an ECA efficient channel attention module was added to its backbone network Backbone, which generated channel weights by one-dimensional convolution and captured small targets that could be easily ignored in tomatoes of different ripening stages by interacting with the k neighboring channels of each channel, thus enhancing the expressiveness and accuracy of tomato features and effectively mitigating the effects of occlusion and light interference on the recognition results. Moreover, the PAFPN in the Neck structure was replaced by BiFPN with bidirectional weighted fusion capability. BiFPN was able to bi-directionally fuse features of different scales, which better handled the occlusion problem between tomato fruits and improves the accuracy of the recognition, and this optimization also mitigated the effect of multi-targets on the recognition accuracy, which enabled the algorithm to perform better in complex scenarios. Finally, a P2 module for small-target detection was added to the Head structure. The P2 module was able to better combine the advantages of shallow and deep tomato features to improve the detection performance of small-target tomatoes, so that it can accurately detect the target even when there are small-target tomatoes and other complex situations in the image. Through a series of ablation experiments, authors obtained the optimal improved algorithm YOLOv5-tomatoA. Compared to traditional target detection networks such as YOLOv3-Tiny, SSD300 and Faster R-CNN, the algorithm performs well in complex scenes such as occlusion and uneven illumination, with an average accuracy mean and F1 score of 97.4% and 95.4%, respectively, and the recognition of an image takes only 14.7ms, which can simultaneously satisfy the high-precision and fast-response tomato fruit recognition. The improved YOLOv5 network structure also optimizes the memory footprint and resource consumption, occupying only 15.9M, making the model more lightweight. This mean that the algorithm had low equipment requirements for realizing online non-destructive testing of tomato ripening, which can provide a more convenient real-time monitoring tool for agricultural activities. This technique can also be applied to the design of automatic tomato picking robots, which provides a strong support to realize the automation and intelligence of the tomato planting process. Therefore, this improved YOLOv5-tomatoA algorithm has important practical value in the field of tomato ripeness detection and is expected to provide more accurate and intelligent management decision support for agricultural production.

Reports on Weather Impacts to Agricultural Production in Summer 2024

WU Men-xin, LI Yi-jun, ZHAO Xiao-feng, HE Liang, LIU Wei

2024, 45(12):  1533-1535.  doi:10.3969/j.issn.1000-6362.2024.12.013

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The relationship between meteorological factors and agricultural production in China was analyzed using statistical methods, based on daily national meteorological data for the summer of 2024. The results showed that the national average temperature in the summer (June−August) was 22.4°C, 1.2°C higher than the average of the same period from 1961 to 2020 and the maximum value since 1961. The national average precipitation was 342.6mm, which was 20.7mm more than the average of the same period from 1961 to 2020. The national average sunshine duration was 630.0h, 35.1h less than the average of the same period from 1961 to 2020. In most of the agricultural region, the sunshine, heat conditions, and soil moisture content were suitable, and general meteorological conditions were favorable for the growth and production of grain crops. At the same time, the frequent meteorological disasters in the summer had a certain effect on the growth and yield formation of the autumn harvest crops. The North China and Huang-Huai region experienced drought and waterlogging, which affected the growth of summer sowing crops. The heavy rainfall occurred in Jiangnan and south China region, and some early rice suffered from "flowering-stage heavy rain" disaster. There was more precipitation in the central and southern parts of northeast China region, which affected the crop growth and yield formation. The Sichuan basin and the middle and lower reaches of the Yangtze river sustained high temperature weather, which affected the growth of single-season rice and local featured crops in some areas.