To investigate the effects of different nitrogen and phosphorus fertilization on the agronomic traits and quality of silage corn in Yuyang District, this experiment used ‘Dajingjiu 23’ silage corn as the research subject and adopted a split-plot design. Nitrogen fertilizer was applied at four levels: 90, 180, 270 and 360 kg/hm²; phosphorus fertilizer was applied at two levels: 90 and 180 kg/hm²; a blank control (CK) without nitrogen or phosphorus fertilizer was also set up as a reference; the effects of nitrogen and phosphorus fertilization on the agronomic traits, yield and quality of silage corn during various growth stages were investigated. The results showed that under low phosphorus treatment (P 90 kg/hm²), the yield-increasing effect of nitrogen fertilizer was more significant; N270P90 treatment performed best during the jointing stage, with N360P90 plants showing a prominent height advantage after tasseling; excessive phosphorus (P 180 kg/hm²) inhibited stem thickening (P<0.05). The fresh grass yield and dry hay yield were the highest under N360P90 treatment, increasing by 37.8% and 39.4%, respectively, compared to CK; nitrogen fertilizer played a crucial role in the accumulation of fresh and dry matter; N270P90 and N360P90 treatments had the highest crude protein content (P<0.05), increasing by 7.52% and 7.49%, respectively, compared to CK; N180P90 treatment had the lowest NDF and ADF content, at 44.31% and 23.37%, respectively, significantly improving feed quality. The comprehensive analysis showed that N360P90 was the optimal combination of nitrogen and phosphorus.

To better understand the fertilization status of farmers at the county scale in Guangdong, and then provide references for formulating scientific fertilizer management strategies and implementing soil testing and formulated fertilization as well as reducing chemical fertilizers and increasing efficiency, the data on crop planting and fertilization throughout the year of 124 farmers in five towns of Boluo County were collected in 2022 by field survey. The overall characteristics of fertilization were analyzed, and a detailed examination was conducted for the fertilization status, partial productivity and application reduction potential of three land use types (paddy fields, vegetable fields, and orchards). The results showed that the input of chemical fertilizer nutrients (N, P₂O₅, and K₂O) in Boluo County was 864.7 kg/hm², while the proportion of organic fertilizer application reached 42.7% and its nutrient input was 326.3 kg/hm². The chemical fertilizers were primarily compound fertilizers, among which the 1:1:1 type accounted for 72.5% of the total chemical fertilizer usage. Organic fertilizers were mainly commercial ones. In terms of fertilization methods, the base fertilizer was mainly applied deeply, while the additional fertilizer was applied superficially mainly. There were significant differences in fertilizer application rates among different land use types, with orchards having the highest nutrient input. Specifically, the nutrient inputs of chemical fertilizers were 580.7, 717.5, and 1051.6 kg/hm² for paddy fields, vegetable fields, and orchards respectively, while the nutrient inputs of organic fertilizers were 37.6, 327.6, and 598.5 kg/hm² respectively. Among farmers using organic fertilizers, the nutrient substitution rates of organic fertilizers in paddy fields, vegetable fields and orchards were 4.6%, 30.3% and 34.9%, respectively. The partial factor productivity of fertilizer nutrients in paddy fields, vegetable fields and orchards was 17.3, 59.7, and 15.1 kg/kg, respectively, and the potential for fertilizer nutrient reduction was estimated to be 49.4%, 33.4%, and 34.7%, respectively. There was an imbalance in the proportion of nitrogen, phosphorus, and potassium nutrient inputs in paddy fields and vegetable fields, with phosphorus overuse being the most significant in vegetable fields. Currently, there are problems such as high fertilizer usage, unbalanced nutrient ratio and backward fertilization methods in Boluo County. It is recommended to reasonably adjust the amount of fertilizer applied to crops, and control the input ratio of phosphorus in order to improve the utilization rate of fertilizers, reduce unnecessary fertilizer waste and promote the sustainable development of agricultural production.

The study aimed to master the quality grade and soil nutrient characteristics of cultivated land in Kongtong District, Pingliang City, Gansu Province, and to provide scientific basis for the future management, protection and utilization of cultivated land quality. Using the cultivated land quality grade evaluation data of 2021 in Kongtong District, the cultivated land quality grade and soil nutrient characteristics in the region were studied based on GIS technology. The results showed that the cultivated land quality in Kongtong District was generally low, and the cultivated land was distributed from 4^th grade to 10^th grade, the 8^th grade land was the main cultivated land. Among them, the 4^th to 6^th grade land accounted for 33.58% of the total area of cultivated land, they were mainly distributed in Sishilipu Town, Baishui Town, Huasuo Town, Caofeng Town, Dazhai Town, Daqin Town and Xiamen Town; the 7^th to 10^th grade land accounted for 66.42% of the total area of cultivated land, they were mainly distributed in Caofeng Town, Dazhai Town, Suoluo Town, Sishilipu Town, Anguo Town, Xiyang Town, Mawu Town and Xiamen Town. The soil organic matter content of cultivated land in Kongtong District was mostly at the low level, with an average content of 14.99 g/kg; the total nitrogen content was mostly at the low and lower levels, with an average content of 0.78 g/kg; the available phosphorus content was mostly at the low and medium level, with an average content of 17.98 mg/kg; the content of available potassium was mostly at the high level, with an average content of 318.67 mg/kg. Among the main soil types, the average content of organic matter and total nitrogen in silted soil was the lowest, while the average content of available phosphorus and available potassium in black loessial soil was the lowest. The key for improving the quality of cultivated land in Kongtong District lies in increasing the application of organic fertilizer, improving nitrogen fertilizer utilization efficiency, intensifying efforts to improve medium and low yield fields, implementing the cultivated land rotation fallow system in line with the actual situation in Kongtong District, improving the degree of intensive use of cultivated land, and promoting the sustainable use of cultivated land resources.

The health of cultivated land is related to the national food security strategy and of great significance for the construction of agricultural power and the modern and high-quality development of Chinese-style agricultural modernization. Studying the health of the arable land in the plateau mountains areas is conducive to protecting the quality and production capacity and ecological environment of cultivated land in ecological fragile areas. In this study, Kunming City was selected as the study area, we constructed the PSR model of arable land health evaluation index system, and utilized the entropy weight TOPSIS method and obstacle degree model to evaluate the arable land health status and diagnose obstacle factors. The results showed that: (1) the pressure, status and response indices of cultivated land in Kunming were 0.315, 0.634 and 0.367, respectively, with health grades of healthy and sub-healthy; the comprehensive index was 0.346, and cultivated land health was in sub-healthy grade. (2) Combined with the agricultural function zoning, the health level of cultivated land in each district and county showed a certain spatial distribution law: the green agricultural demonstration area in Dianchi Lake Basin is centered on Dianchi Lake, and the surrounding basin was low and the periphery was high. The efficient modern agricultural area around the main city took the northeast-southwest as the main axis, and gradually decreased from the axis to the outside. The northern mountainous characteristic ecological agricultural area was high in the south and low in the north. (3) The primary factor affecting the overall cropland health in Kunming was cropland pressure, followed by cropland status, and finally cropland response. Among them, the population density, use of pesticide, use of agricultural fertilizer, cropland planting structure, and use of agricultural plastic film were the main influencing obstacle factors.The inclusion of high standard farmland construction potential cropland ratio and integrated soil and water management area indicators into the PSR model of cropland health evaluation index system is operable and could effectively evaluate the level of cropland health and provide strategies for cropland protection.

To explore the optimal fertilization ratio and amount of Aconitum georgei Comber. in Lijiang City, Yunnan Province, and to provide suitable fertilization scheme for fertilizer reduction and efficiency enhancement of the Aconitum georgei Comber, the effects of different nitrogen, phosphorus and potassium ratios on the yield, growth multiple and individual weight of the fresh roots tuber of Aconitum georgei Comber. were studied based on the ‘3414’ fertilization design. Application amount of N, P and K was simulated using fertilizer effect function equation, and the interaction effects of N, P and K was analyzed.The results showed that the ratio of N, P and K had significant effects on root stock yield and weight of roots tuber, but had no significant effect on multiple of roots tuber. The effect of the three kinds of fertilizers on the yield was P fertilizer>N fertilizer>K fertilizer, and the effect of appropriate nitrogen and phosphorus was the best; The actual roots tuber yield, growth multiple and individual weight of the N2P2K3 were the highest, which was 6512.39 kg/hm², 1.51 times and 15.55 g every individual, respectively; effect of N, P and K on roots tuber yield of Aconitum georgei Comber. was interactive. The regression analysis results showed an atypical ternary quadratic fertilizer effect model existing between N, P and K fertilization rates and roots tuber yield, but binary quadratic function and unary quadratic function failed to give proper regression. Yield frequency analysis was used to determine the proper recommended fertilizer application amount. The optimal fertilization ratio was N2P2K3 (nitrogen, phosphorus and potassium were 138.00, 120.00 and 351.00 kg/hm², respectively); a combination medium P and medium K was advantageous to N efficiency, a combination medium N and medium K was advantageous to P efficiency, a combination medium N and medium P was beneficial to K efficiency. The recommended amount of nitrogen fertilizer was 99.66-127.21 kg/hm², phosphorus fertilizer was 80.94-110.42 kg/hm² and potassium fertilizer was 157.82-215.32 kg/hm², the corresponding ratio was 1:0.64-1.10:1.24-2.16 by the roots tuber yield frequency analysis.

To explore the role of organic fertilizer application in the growth and nitrogen metabolism of flue-cured tobacco under the condition of chemical fertilizer reduction, the field experiment was conducted. Using flue-cured tobacco variety ‘Yunyan 87’ as the test material, five treatments were set up, including conventional fertilization (CK), chemical fertilizer reduction of 10% (T1), chemical fertilizer reduction of 10% + sesame cake (T2), chemical fertilizer reduction of 10% + humic acid (T3), chemical fertilizer reduction of 10% + sesame cake + humic acid (T4), to study the effects of fertilizer reduction combined with different organic fertilizers on the agronomic traits, dry matter accumulation, nitrogen metabolism related indicators, chemical composition and economic traits of flue-cured tobacco. The results showed that the reduction of chemical fertilizer reduced the agronomic traits and dry matter accumulation of tobacco plants. Compared with the chemical fertilizer reduction treatment, the plant height increased by 2.18%-5.28%, the stem circumference increased by 5.84%-9.06%, and the dry matter accumulation increased by 26.80%-39.88% in the organic fertilizer application treatments, respectively. Combined application of organic fertilizer had a certain effect on nitrogen metabolism, increased SPAD value, protein content, and the activities of asparagine synthetase, glutamic oxaloacetate aminotransferase and alanine aminotransferase to varying degrees. The combined application of organic fertilizer increased the yield and output value by 6.32%-14.57% and 3.35%-14.55%, respectively, compared with the chemical fertilizer reduction treatment, and also increased by 2.61%-10.58% and 2.79%-13.93% compared with CK; compared with the chemical fertilizer reduction treatment, the partial productivity of nitrogen fertilizer and the partial production efficiency of nitrogen fertilizer increased by 6.32%-14.57% and 3.35%-14.55%, respectively, and also increased by 14.01%-22.86% and 14.21%-26.59% compared with CK. The combined application of organic fertilizer has a certain alleviating effect on the decrease of nicotine, total nitrogen and potassium content, and the increase of sugar content and sugar-alkali ratio caused by chemical fertilizer reduction, and the chemical composition and coordination index are closer to the suitable range of high-quality tobacco leaves. In terms of comprehensive effect, sesame cake fertilizer is the best.

5-Aminolevulinic acid (5-ALA) is widely present in animals, plants, and microbial cells and serves as a key precursor for tetrapyrrole compounds. It participates in the synthesis of essential metabolites such as heme, vitamin B₁₂, and chlorophyll, exhibiting diverse physiological functions. This paper summarized the biosynthesis pathway of 5-ALA and its transport mechanism across different cell types, analyzed the functions and regulatory mechanisms of important downstream metabolites derived from 5-ALA, and reviewed the current applications of 5-ALA in pharmaceutical and agricultural fields. Furthermore, this paper highlighted existing challenges, including immaturity of biosynthesis technology and lack of standardized application protocols, and provided future research prospects to guide its potential applications in agriculture.

To investigate the effects of different additives on the quality of broomcorn millet stem and leaf silage and to find the optimal silage conditions for broomcorn millet stem and leaf, an experiment was conducted using 'Qishu 1' broomcorn millet stems and leaves after harvesting the grain as raw materials. Five addictive treatments were set up, including Lactobacillus plantarum (0.02‰), sucrose (2.0%), cellulase (0.05‰), urea (4%), and a control without additives. The samples were collected and measured for nutrient content and fermentation quality at 20℃ for 50 days. The results showed that the sensory evaluation of all additive treatments was better than that of the control. The DM and CP contents of T₁ treatment were the highest, at 37.23% and 3.69%, respectively, which were significantly higher than those of the control. The NDF content of T₃ treatment was the lowest (57.73%), which was significantly lower than that of the control. The WSC content of T₄ treatment was the highest (1.62%), which was significantly higher than that of the control. The additives significantly reduced the pH and NH₃-N content of broomcorn millet stem and leaf silage and improved its aerobic stability. The pH range of the different additive treatments was 3.56-3.96, the NH₃-N content range was 2.75%-3.53%, and the AS range was 87-113 h. In summary, the additive treatments improved the quality of broomcorn millet stem and leaf silage. Using fuzzy membership function calculation, the best quality of broomcorn millet stem and leaf silage was obtained in the Lactobacillus plantarum treatment, followed by the cellulase treatment.

This study selected the meteorological observation data of Ningxian County, which is the largest and most representative apple planting area in Longdong from 2011 to 2023, and the apple rot disease data of Ningxian Agricultural Technology Extension Centertoanalyze the occurrence mechanism of apple rot disease in Longdongusing statistical and correlation analysis methods. The results showed that apple rot disease of the most severe impact on production occurred in spring, starting in late March, with the highest incidence from April to May and a significant decrease in June; the interannual variation showed that 2011-2013 was the period with a high incidence of apple rot disease and an increasing trend year by year. The occurrence area of apple rot disease showed a decreasing trend from 2014 to 2019, 2018 was the lowest value in 13 years, 2020 was the year of apple rot disease outbreak, and the incidence area of apple rot disease gradually decreased from 2021 to 2023; the average temperature during the flowering period had a positive impact on rot disease, while during the swelling period, it had a negative impact; the highest temperature during the fruit enlargement period had a negative impact on rot disease; the lowest temperature at each stage had a negative impact on rot disease; the average relative humidity had a negative impact during the flowering period and a positive impact during the fruit enlargement period. The impact of precipitation on rot disease was mainly manifested in a positive impact during the fruit enlargement period; wind speed and sunlight had a positive impact during the flowering period and a negative impact during the fruit enlargement period; a regression model was established for the high incidence period in spring based on significant meteorological factors, and the established regression model was tested. The fitted values were consistent with the measured results, indicating that the established prediction model can be applied to the prediction of rot disease. This study is of great significance for improving the output value of Longdong fruit industry and promoting rural economic revitalization.

According to the wheat dry-hot wind disaster grade (QX/T 82—2019) standard, the number of dry-hot wind days, the weather process, the annual type and occurrence time of dry-hot wind in this period were investigated. The occurrence law of dry and hot wind disasters in Zhaoyuan and its impact on winter wheat were summarized, and the corresponding defensive methods were put forward. Based on the meteorological observation data and wheat growth period observation data from 1978 to 2023 in Zhaoyuan City, the dry hot wind of high temperature and low humidity type from May 21 to June 10 and the dry hot wind of post-rain green type from June 1 to June 10 were studied using Mann-Kendall mutation test and linear regression. The results showed that wheat dry hot air was mainly light type, both annual and internal changes showed periodic oscillations, the linear trend showed a slow decline, the mutation point was 2004, and it rose linearly to the highest value and then decreased. The integrated technology of green, high quality and efficient production of wheat with the goal of improving fertilizer and water control ability, crop resistance ability and dry hot air defense ability can reduce the harm of dry hot air to wheat and provide technical support for wheat production in Zhaoyuan.

The study aims to explorethe time series dynamic relationship between meteorological conditions and the yield of chili peppers in the Qiannan region,and lay a solid theoretical foundation for production planning, climate adaptability analysis, and future yield prediction of the chili pepper industry in this area. Four methods, namely the single exponential smoothing method, the quadratic exponential smoothing method, the 3-year moving mean method, and the HP filtering method, were adopted to separate the unit yield data of peppers in Qiannan region from 2013 to 2022 into the trend yield and meteorological yield of peppers. Through correlation analysis, the main meteorological factors affecting yield of pepper were screened out. Subsequently, a stepwise regression model was used to construct a prediction model for the meteorological yield of peppers. According to research findings, (1) four different methods for separating yield all effectivelyreflected the consistency characteristics of the meteorological yield sequence and the changes in meteorological disasters in Qiannan. Among them, the trend yield separated by the single exponential smoothing method could efficiently capture the more intense fluctuation parts in the yield; (2) in the meteorological yield prediction model of peppers, except for Duyun and Guiding, the R² of the meteorological yield prediction model of peppers in the other counties ranged from 0.728 (Longli) to 0.998 (Fuquan), and all passed the 99% confidence test. Except for Pingtang, Sandu, Fuquan and Duyun, the prediction models based on meteorological factors constructed for the remaining counties performed well in simulating the yield of peppers, and the model accuracy and prediction accuracy were relatively high, which can be applied to the estimation of pepper yields.

In order to understand the spatial and temporal distribution characteristics of climate change and meteorological disaster risk in tobacco-growing areas of Hengyang, based on the meteorological data from 1971 to 2020 in 5 counties and cities of Hengyang tobacco-growing area, the temporal and spatial distribution characteristics of climate change and meteorological risk were quantitatively analyzed by linear trend analysis and correlation analysis. The results showed that in the past 50 years, the average field temperature in the tobacco-growing areas of Hengyang increased significantly, the fluctuation of precipitation increased significantly, and the average sunshine hours decreased significantly. The risk of low temperature was mainly concentrated in the elongation stage. The risk of low temperature in Hengnan County and Hengyang County was relatively high and had a decreasing trend in recent years. The risk of high temperature mainly occurred in the later stage of maturation. The risk of high temperature in the southern region, centered in Changning, was relatively high. The increase of high temperature risk in the mature stage was significantly positively correlated with the increase of average temperature, there was a significant negative correlation between the risk of high temperature and precipitation. The southern regions of Changning and Leiyang had a relatively high rainstorm risk with an increasing trend, which may be related to the increase of rainfall in the later stage of maturity. In Leiyang, the drought degree at the elongation stage was more obvious and showed an increasing tendency, while the drought risk was relatively higher at the peak-early maturity stage in Hengyang County and Qidong County, and the drought risk was alleviated in other counties except Hengyang County. Finally, several practical recommendations are proposed for production. Preventive measures should be implemented at different growth stages to address varying meteorological risks, mitigating the adverse effects of weather disasters on tobacco growth and quality.