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Evapotranspiration is an important component of the water cycle, influencing crop growth and grain production. Obtaining long-term, high-resolution evapotranspiration data can help optimize regional water resource allocation. Using Landsat and MODIS remote sensing data, along with ground observation flux data and meteorological data, the SEBS model and ESTARFM model are utilized to derive high spatiotemporal resolution evapotranspiration estimates for the southern red soil area from April to October 2019. The spatiotemporal variation characteristics and influencing factors of the high resolution evapotranspiration are analyzed. The results show that high spatial resolution remote sensing images can achieve higher accuracy in simulating remote sensing-based evapotranspiration. The simulation performance of the SEBS model driven by Landsat remote sensing data is better than that of the SEBS model based on MODIS data. Comparison between the high spatiotemporal resolution evapotranspiration obtained by the ESTARFM model and the measured evapotranspiration using a large aperture scintillometer shows a RMSE of 0.68mm·d-1 and R² of 0.87. The simulated high spatiotemporal resolution daily evapotranspiration from April to October 2019 is spatially correlated with land use types, with evapotranspiration rates as follows: forest > paddy field > other agricultural land. Temporally, evapotranspiration showed an increasing trend from April to August, followed by a gradual decrease from August to October. Temperature is found to be the main meteorological factor affecting evapotranspiration in the study area. The high spatiotemporal resolution evapotranspiration obtained using the SEBS and ESTARFM models shows good agreement with ground measurements. The combination of the SEBS and ESTARFM models can serve as an effective tool for estimating evapotranspiration in southern red soil regions. [ABSTRACT FROM AUTHOR]

[Objectives] This paper aimed to study the interaction mechanism of straw-soil-strip vertical rotary tillage system in rice stubble field, explore the influence of key operation parameters under the interaction of the three on the clearing and leveling effect of seedbed, and play a guiding role in the integrated straw field management and the optimal design of tillage machinery in the water-drought rotation system. [Methods] A 3D vertical rotation simulation model was constructed based on discrete element method. The process of vertical strip rotation under rice straw mulching was simulated, and the parameter range was optimized and verified by laboratory soil tank test. In the process of strip vertical rotation, the forward speed, the rotational speed of tool shaft and the stubble length were taken as the influencing factors. The response surface method was used to build a mathematical model to analyze the influence of each factor on the quality of the seedbed and carry out the performance optimization test. [Results]When the tillage depth was set to 15 cm, the main and secondary factors affecting the cleaning rate of stubble and the flatness of seedbed were the forward speed, the tool shaft rotational speed and stubble length. The results of multi-objective optimization showed that the quality of seedbed was the best when the tool forward speed was 1.09 m·s-1, the tool shaft rotational speed was 281.5 r·min-1 and the stubble length was 6.89 cm. The straw cleaning rate of seedbed was 81.95% and the seedbed flatness was 8.67 mm. [Conclusions] The interaction model established in this paper was proved to be reliable and could effectively reflect the effect of vertical rotation operation parameters on the clearing of straw in seed bed. [ABSTRACT FROM AUTHOR]

To study the relationship between soil phosphorus content and soil phosphatase activity, the paddy soils in the karst area (KA) and non - karst area (NKA) of the Mao Village experimental field in Guilin City were selected as research subjects. Total phosphorus, available phosphorus, inorganic phosphorus components, and alkaline phosphatase activity in the soil were investigated. The results revealed low total phosphorus content in the KA soil, with abundantly available phosphorus content characterized by Fe-P, Ca8-P, and Ca10-P as the main inorganic phosphorus components. Alkaline phosphatase activity ranged from 0.76~1.27 mg ∙ kg-1 in the KA soil. In contrast, the NKA soil exhibited extremely low total phosphorus content, and moderate available phosphorus content. The main inorganic phosphorus components were Fe-P, Ca10-P, and Al-P, with alkaline phosphatase activity ranging from 0.06~0.35 mg∙kg-1 . The contents of total phosphorus and available phosphorus and alkaline phosphatase activity were significantly higher in the KA soil than in the NKA soil. Alkaline phosphatase activity in both the KA and NKA soils had a negative correlation with available phosphorus. In the KA soil, Fe-P content showed a significantly positive correlation with alkaline phosphatase activity, while in the NKA soil, total phosphorus, Ca8-P, and Al-P were all significantly negatively correlated with alkaline phosphatase activity. These findings suggest that available phosphorus and inorganic phosphorus fractions may be crucial factors influencing the differences in soil alkaline phosphatase activity between the KA and NKA soils. [ABSTRACT FROM AUTHOR]

Intestinal microbiota plays a crucial role in the nutritional metabolism and immune functions of animals. In order to investigate the impact of two cultivation modes, namely grass-based shrimp farming and paddy field shrimp farming, on the intestinal microbiota and muscle flavor of Macrobrachium rosenbergii, this experiment focused on specimens raised in different cultivation areas with the same breeding cycle. The specimens were categorized into a grass-based cultivation group (Grass Group) and a paddy field cultivation group (Paddy Group). The study conducted analyses on the structure of intestinal microbiota, muscle amino acids, and trace elements in the muscle content. Firstly, at the phylum level classification of shrimp intestinal microbiota, Firmicutes, Proteobacteria, and Tenericutes were identified as dominant phyla under both cultivation modes (with a relative abundance > 5%). Additionally, Cyanobacteria and Bacteroidetes were identified as specific dominant phyla in the Grass Group. At the genus level classification, Lactococcus, Enterobacter, and Candidatus_Hepatoplasma were identified as dominant genera in both groups. Secondly, in terms of microbiota diversity analysis, the number of operational taxonomic units (OTUs) in the Paddy Group was significantly higher than that in the Grass Group, indicating a higher species diversity of intestinal microbiota in Macrobrachium rosenbergii under paddy field cultivation. The functional prediction of the intestinal microbiota revealed that the functions in both cultivation modes were mainly concentrated in metabolic regulation pathways. Finally, in the analysis of nutritional components and the evaluation of muscle flavor, it was proved that there was no significant difference in the total contents of umami amino acids and sweet amino acids between them. However, the Paddy Group exhibited significantly higher levels of serine, glycine, and arginine in the muscle compared to the Grass Group. The iron content in the muscle of Macrobrachium rosenbergii under paddy field cultivation was significantly higher, while copper and zinc content were significantly lower compared to the Grass Group. There were no significant differences in the content of other mineral elements. In conclusion, Macrobrachium rosenbergii under paddy field cultivation exhibited superior muscle flavor and a more diverse intestinal microbiota. The results of this study can provide technical references and guidance for different health cultivation modes of Macrobrachium rosenbergii. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Agrometeorology is the property of Editorial Board of Chinese Journal of Agrometeorology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Barnyard grass is a typical weed in paddy fields that can severely affect the growth and development of rice, ultimately leading to reduced yields. Its appearance is very similar to that of rice, making it difficult to distinguish and posing significant challenges for management. Ideal conditions for barnyard grass identification are achievable in controlled indoor settings but are difficult to replicate in practical applications. For this reason, identifying and mapping barnyard grass in complex paddy field environments holds significant research value and importance. First, hyperspectral images of the paddy fields were captured using UAVs. After image stitching, rectification, and SG (Savitzky-Golay) convolution filtering, a sequential projection algorithm (SPA) was employed to extract sensitive bands for distinguishing rice from barnyard grass. Modeling was performed across the entire spectral range and selected feature bands, employing support vector machines (SVM), random forests (RF), one-dimensional convolutional neural networks (1DCNN), and three-dimensional convolutional neural networks (3DCNN). The results indicated that SPA-3DCNN achieved the best recognition performance for rice (0.9420) and barnyard grass (0.893 6). The seven feature bands selected by SPA (482.523 4, 546.541 5, 675.080 6, 709.138 2, 762.043 1, 922.015 7, and 944.637 1 nm) were valuable for distinguishing barnyard grass from rice. Subsequently, the model was applied to the entire hyperspectral dataset to generate spatial distribution and density maps of barnyard grass. This study successfully explored the feasibility of UAV-based hyperspectral identification of barnyard grass in complex paddy field environments, providing strong data support for the management and prevention of barnyard grass. [ABSTRACT FROM AUTHOR]

Based on the actual distribution data of Guizhou kam sweet rice in field records and literature, the Maximum Entropy Model (MaxEnt) optimised by the Kuenm packet was used to study the suitable regions of Guizhou kam sweet rice and the dominant climatic factors affecting the distribution of kam sweet rice under the historical and future climate scenarios, which provides a reference basis for rational planning of distribution of kam sweet rice production in the context of climate change. The results showed that: (1) during the historical period of 1970-2000, the potential suitable region of kam sweet rice were mainly concentrated in the southeastern part of Qiandongnan prefecture, Guizhou province, and the highly suitable regions were distributed in Congjiang, Rongjiang, and Liping counties. (2) Compared with the historical period, the highly suitable region of kam sweet rice under the SSP126 climate scenario increases in region and moves to higher altitude in 2041-2060, and decreases in region and moves to higher latitude in 2081-2100, and increases in region and moves to higher latitude in 2041-2060, and decreases in region and moves to higher latitude in 2081-2100 under the SSP245 climate scenario. In the SSP585 climate scenario, the highly suitable region of kam sweet rice increases in region and moves to higher altitudes in 2081-2100. (3) Among the 19 climate impact factors, the min. temperature of the coldest month and the mean diurnal range difference are the main climate factors affecting the distribution of kam sweet rice, with contribution rates of 34.8% and 13.8%, respectively. Generally speaking, climate change will lead to the expansion of the highly suitable region of kam sweet rice in 2041-2060 and the reduction of the region in 2081-2100, so it is necessary to pay attention to the climate change, and rationally plan the production layout of kam sweet rice to ensure the food security. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ecology & Rural Environment is the property of Journal of Ecology & Rural Environment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The integrated rice-Azolla imbircata cropping is a traditional rice cultivation way in China, which can improve the rice yield and nitrogen use efficiency. However, few studies have focused on the effect of integrated rice- Azolla imbircata cropping on the phosphorus fertilizer use efficiency in rice. A field experiment was conducted to investigate the effects of the treatment of integrated rice-Azolla imbircata cropping on the soil physical and chemical properties in paddy field, rice yield and the utilization efficiency of phosphorus fertilizer. The results showed that the treatment of integrated rice-Azolla imbircata cropping did not significantly change the contents of soil organic matter, total nitrogen, total phosphorus and available phosphorus, but significantly increased the content of nitrate nitrogen in soil (P< 0.05). The integrated rice-Azolla imbircata cropping promoted the acquisition of phosphorus in rice, significantly increased the phosphorus uptake in grain (P<0.05) and the total phosphorus uptake in the aboveground part (P<0.05). In addition, the integrated rice-Azolla imbircata cropping also improved the recovery and utilization rate of phosphate fertilizer in rice (P<0.05), indicating that the treatment of integrated rice-Azolla imbircata cropping could effectively improve the utilization efficiency of phosphate fertilizer in rice, which provided a reference way for the efficient utilization of phosphate fertilizer in rice. [ABSTRACT FROM AUTHOR]

Data from national meteorological stations in 90 counties of Jiangxi province during 2012-2021 and 8 microclimate stations in rice fields during 2017-2021 were used to analyze the differences in temperature between rice fields and stations, and the statistical results based on H1 (NS)(daily max temperature of national stations ≥35 °C), H1 (RS)(daily max temperature of rice fields ≥35 °C), H2 (NS)(daily max temperature of national stations ≥37°C) and H2 (RS) (daily max temperature of rice fields ≥ 37 °C ) were compared. Furthermore, proposing high-temperature damage indicators more suitable for early rice in Jiangxi, which would promoting capabilities of high-temperature monitoring and defense. The results showed that: (1) compared with the national stations, the rice fields had a cooling effect, and the Tmax(daily maximum temperature), T(daily average temperature), and Tmin(daily minimum temperature) were 0.6 °C, 0.4 °C, and 0.3 °C lower than national stations. What's more, the cooling effect increased with the growth of early rice, which showed as heading-maturity period>transplanting-booting period>sowing-transplanting period. (2) The cooling effect was higher in sunny days than in cloudy and rainy days during the high temperature period, and T, Tmax and Tmin of early rice field were 0.7 °C, 0.8 °C and 0.6 °C lower than that of the national stations. On cloudy and rainy days, the decrease in temperature of rice fields was similar. (3) There were significant differences in daily and hourly air temperature between 6 rice fields and the corresponding national stations during H1 (NS) heat damage occurred, and the cooling intensity of the rice field was greater at night than in the daytime. The Tmax, T and Tmin of the 6 fields were generally about 1.2 °C lower, which was strongest in Jinxi filed with T, Tmax and Tmin was 1.5 °C, 1.1 °C and 2.6 °C lower. (4) H1 (NS) was the largest and H2 (RS) was the smallest in terms of the number of counties affected by heat damage, the average duration, the average yield reduction simulation value of affected counties and the simulation value of the whole in recent 10 years based on different heat damage index. There was no significant difference in the result of average duration, the simulated average yield reduction rate of affected counties, and the simulated yield reduction rate of the whole based on H2 (NS) and H1 (RS), while they were all different with the result based on H1 (NS) or H2 (RS). And the simulated value of the reduction rate of the whole calculated by H2 (NS) was closer to the actual value. Therefore, national stations Tmax ≥37°C was more suitable as an index of heat damage for early rice in Jiangxi. [ABSTRACT FROM AUTHOR]

[Objective] This study analyzed the distribution of root-knot nematodes (RKNs) in rice producing areas in northern China to provide strategies for nematode control. [Method] In spring of 2020 and 2021, 1 032 soil samples were collected from continuous paddy fields, surrounding field ridges and dry croplands from 13 provinces (municipality/autonomous region)in northern China, including Henan, Shandong, Ningxia, Beijing, Jilin, Heilongjiang, Xinjiang, Gansu, Hebei, Liaoning, Shanxi, Shaanxi and Inner Mongolia. Each soil sample was mixed with autosaved sand and divided into three sub-samples, and rice and omato were used as baiting plants to form galls, which were checked after 50 d. Perineal patterns were made on selected adult females to generate morphological features and 6 pairs of specific primers were used o identify the RKN species as molecular tools. [Result] A total of 11 9 soil samples were able to form root galls on baiting roots of rice or tomato. The overall relevance ratio was 11.53% and Ningxia had the highest relevance ratio of 33.33%. In identified samples, Meloidogyne graminicola was the dominant species with relevance ratio of 96.83%. The relevance ratios of M. arenaria, M. hapla, M. incognita, M. enterolobii and M.javanica were 84.1 3 %, 52.38%, 31.75 %, 15.87 % and 3.1 7 %, respectively. The ratios of PCR detected soil samples infested by 1, 2, 3, 4, 5 and 6 of RKN species were 11.11 %, 28.57%, 28.57%, 28.57 %, 3.1 8 % and 0 %, respectively. The mixture of M. graminicola, M. incognita, M. arenaria and M. hapla had the highest infection ration of 23.81 %, followed by M. graminicola and M. arenaria mixture (22.22%) and M. graminicola, M. arenaria and M. hapla mixture (15.87%), while those of other mixtures were below 10.00%. [Conclusion] RKNs were widely distributed in paddy fields and surrounding environment in northern China, among which M. graminicola was the dominant species. M. enterolobii had also spread and adapted to low temperature from south to north. Strengthening the study of RKNs adaptability and formulating corresponding control measures are suggested. [ABSTRACT FROM AUTHOR]

Weeds have posed a serious impact on rice growth and yield in paddy fields. In this study, an inter-row weeding device was designed in the paddy field, including a pressing-weeds floating plate and a weeding roller. The weeding procedure was that the floating plate pushed over the weeds in the inter-row area, and then the weeding roller pressed the weeds into the soil. The probability that the weeding roller pressed the weeds into the soil was improved by 9.98% after the floating plate was pushed over the weeds. Furthermore, the pressing-weeds floating plate was in a closed box structure, which gradually pushed over the weeds, reduced the forward resistance and moved the rice for less damage to the stems and leaves. The weeding roller was composed of weeding discs and weeding cutter teeth. The weeds were pressed into the soil to isolate them from sunlight and air, in order to achieve the purpose of weeding. The two ends of the weeding roller were equipped with the chamfer, in order to reduce the damage to rice roots. The weeding width was expanded by 3%, compared with the regular weeding roller. Some parameters were determined, including the expanded weeding width, chamfer angle, soil depth, root crown root angle and weeding width of the weeding roller. The simulation test was implemented to clarify the interaction between the weeding device and soil. The quadratic orthogonal rotation combination test was carried out to analyze the effect of the weeding depth and weeding speed on the amount of heaped soil on the floating plate, the amount of soil disturbance, and the force of the floating plate and weeding roller in the horizontal and vertical directions. The interaction relationship between the factors and test indexes was determined by variance significance and response surface method (RSM). As such, the optimal weeding parameters were determined: the weeding depth was 35 mm, and the weeding speed was 0.8m/s. The field experiment was conducted to analyze the effects of different weeding modes on the plant height, yield, and roots of rice. Four treatments were set: non-weeding, chemical, artificial and mechanical weeding using this inter-row weeding device. Among them, three widths 150, 175, 200 mm and two types with/without chamfer were selected in the weeding rollers. A systematic investigation was made to determine the effect of different types of weeding rollers on the weeding rate, rice roots, rice growth and yield. The experimental results showed that the weeding rate of the device reached 87.51%, which fully met the requirements in the paddy field. The weeding device was also used to turn the soil and increase the permeability of the soil. The weeding rate increased gradually with the increase in the width of the weeding roller. There was an increase in the weeding rate of 7.3% by expanding the inter-row weeding area. There were also significant effects among different weeding modes on the plant height and yield of rice（P＜0.05）. Mechanical weeding can be expected to promote the growth of rice. The yield can also reach or even exceed the levels of chemical and artificial weeding. The weeding roller with different parameters has a significant impact on the weeding rate, plant height, yield and roots of rice. The weeding roller with chamfer at both ends when increasing the width of the weeding roller can effectively avoid or reduce damage to the roots of rice, for better growth of rice, yield and weeding performance（P＜0.05）. The inter-row weeding device can provide a strong reference to the design of weeding machinery and equipment in paddy fields. [ABSTRACT FROM AUTHOR]

【Objective】 Nitrogen loss from soils is a pervasive environmental issue facing agricultural production in many countries. In this paper, we studied the combined effect of rainfall and fertilization on nitrogen loss via surface runoff from paddy fields in attempts to improve nitrogen management and reduce the nonpoint source pollution of rice production in Southern China. 【Method】 The experiment was conducted from 2019 to 2021 in a paddy field in Zhejiang province. It consisted of four nitrogen treatments: conventional nitrogen fertilization (N18), reduced nitrogen fertilization (N15), organic fertilization (OF). Without fertilization was the control. In the experiment, we measured surface runoff, total nitrogen concentration in the surface runoff. The rainfall data were obtained from a weather station on the experimental site. 【Result】 ① Annual rainfall and annual nitrogen loss were closely correlated, but linear regression analysis showed that daily rainfall and total nitrogen did not correlate significantly. Considering the delay between rainfall and nitrogen loss vial the surface runoff can make piecewise average daily rainfall positively correlated to nitrogen loss, with the regression coefficient ≥0.36. ② The effect of fertilization on nitrogen loss from the runoff was ranked in the order of N18>N15>OF>CK. ③ Structural equation showed that, when considering the delay between rainfall and nitrogen loss, the piecewise average daily rainfall, the runoff volume, rainfall interval, the interval between rainfall and fertilization, fertilization amount, and fertilizer types were the factors affecting nitrogen loss, with their standardized total effect being 0.264, -0.126, 0.078, 0.033, and -0.038, respectively. The rainfall affected nitrogen loss more than the fertilization, and the piecewise average daily rainfall and rainfall interval were key factors affecting nitrogen loss. 【Conclusion】 For rice-wheat rotation cultivation in Zhejiang Province, a short rainfall interval affected nitrogen loss via surface runoff from paddy fields more than an increase in rainfall. Applying organic fertilizer in the wet season can reduce nitrogen loss from the runoff.

【Objective】 Reducing nitrogen loss from leaching and emissions is essential to increasing nitrogen fertilizer use efficiency in developing sustainable agriculture. This paper is to propose an optimization of water and carbon to reduce ammonia volatilization from paddy fields. 【Method】 The DNDC model was used to simulate the processes involved in ammonia volatilization; it considered the effects of both water and biochar application. The model was validated against field measurements, and it was then used to investigate the changes in ammonia volatilization from paddy fields under different combinations of irrigation and biochar addition, from which the optimal irrigation and biochar application that gave the least ammonia volatilization and gas emissions was determined. 【Result】 The relative errors between the simulated and measured ammonia volatilization were less than 8%. The model hence accurately captured the fundamental processes underlying ammonia volatilization from paddy fields. When irrigation was the same, increasing biochar addition reduced ammonia volatilization. When biochar addition was the same, reducing irrigation amount reduced the ammonia volatilization. Irrigation and biochar application significantly influenced ammonia volatilization, but ammonia volatilization was more sensitive to irrigation than to biochar addition. 【Conclusion】 Among all treatments we compared, the combination I3+B11 was the optimal irrigation and biochar application for reducing ammonia volatilization from paddy fields. Rationally increasing biochar application combined with a decrease in irrigation amount can effectively reduce ammonia volatilization and gas emissions from paddy fields.

To understand the changes of spring weed community diversity and the correlation with soil nutrients under different long-term fertilization models, a field investigation based on a continuous 24-year long-term fertilization test was conducted in winter fallow paddy field in the yellow soil area of Guizhou Province, China, under a single-rice cropping system. The different treatments were unbalanced fertilization (NP, PK, NK), constant fertilizer (NPK), single organic fertilizer (M), 1/2 organic fertilizer instead of chemical fertilizer (1/2 MNP), and no fertilization (CK) . The results showed that spring weed density, biomass, and community diversity all changed under the conditions of the different long-term fertilization modes. Under the M treatment, soil nutrients were all higher, and the total density and total biomass of the weed community were both highest (1 208.44 plants·m-2 and 1 071.24 g·m-2, respectively) . Compared with the CK treatment, the total density of weeds was 37.74% higher, and the total biomass was 179.58% higher. These results indicated that the M treatment improves soil nutrients and increases weed density and biomass in spring. The different treatments had different effects on the weed community. Under the long-term single application of organic fertilizer (M), Polypogon fugax did not occur. Under the condition of long-term use of inorganic fertilizer, the density of Poa annua was lowest, from 0 – 4.89 plants ·m-2, and under phosphorus deficiency,Alopecurus japonicus was suppressed, showing its lowest density (36.00 plants·m-2) . These results indicated that the different long-term fertilization treatments could inhibit the occurrence of different weeds. In terms of weed biodiversity, the weed community diversity index increased, the dominance index decreased, and the weed community structure was relatively complex under the condition of the nitrogen deficiency. On the contrary, the diversity index decreased, the dominance index increased, and the community structure was relatively simple under phosphorus deficiency. Our results indicated that total nitrogen, alkaline nitrogen, and total phosphorus were the key factors affecting weed density. Hence, reasonable fertilization can control the damage caused by weeds in the field and stabilize soil fertility and species diversity. Moreover, it can promote the agricultural ecosystem to its maximum ecological effect. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] The effects of total replacement of chemical fertilizer with pig manure, cattle manure and chicken manure on nitrogen and organic matter contents in paddy soil and rice yield were investigated in paddy field. [ Method] The rice field experiment was conducted in Gusheng village, Dali city, Yunnan province, with the principle of equal nitrogen full substitution. A total of 5 treatments were set up for the experiment. CKl was the non-fertilizer control, CK2 was the chemical fertilizer control, Tl was pig manure total fertilizer substitution treatment, T2 was cow manure total fertilizer substitution treatment, and T3 was chicken manure total fertilizer substitution treatment. [ Result] Compared with CK2, Tl and T3 treatments significantly increased the soil total nitrogen content by 4. 89% and 3. 83%. Compared with single fertilizer application, the content of ammonium nitrogen in soil of total manure substitution treatment decreased by 19. 36% - 29. 18%, and the content of nitrate nitrogen in soil showed opposite results, and T3 > T2 > Tl > CK2, indicating that total manure substitution treatment increased the risk of soil nitrogen leaching. The three manure substitution treatments could significantly increase soil organic matter content compared with the single fertilizer treatment, and it increased with the increase of C/N ratio of manure, and the increase range was 37. 52 % to 85. 98 % . The order of rice yield was T3 ( 10 399. 92 kg/hm2 ) > CK2 ( 9690. 85 kg/hm2 ) > Tl ( 9512. 39 kg/hm2 ) > T2 (8241. 55 kg/hm2 ) > CK! (7985. 96 kg/hm2 ). Compared with CK2 treatment, T2 treatment significantly reduced rice yield by 14. 96%, and Tl and T3 treatment had no significant difference in rice yield compared with CK2 treatment. There was no significant difference in rice yield composition between the total manure substitution treatments and the CK2 treatment. Tl and T3 handling the amounts of accumulated nitrogen of rice plants and nitrogen absorption efficiency than CK2 treatment had no significant difference. [ Conclusion] Comprehensive fertilizer input cost, pig manure replacement treatment can increase the soil total nitrogen (TN) and organic matter ( SOM) content under the premise of stable yield, that is, stable yield can improve the soil fertilizer supply capacity. Compared with the total replacement treatment of chicken manure, pig manure reduces the risk of nitrogen leaching loss, and is a better alternative manure type for the total substitution of chemical fertilizer. [ABSTRACT FROM AUTHOR]

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Objective Reclaiming the saline coastal soils in eastern China is crucial for ensuring food security. Given the significance of soil carbon in soil quality, this paper investigates the change in soil organic carbon and phosphorus in the soil following initiation of reclamation. Method The experiment was conducted in the northern regions of Hangzhou Bay and Yueqing Bay in eastern Zhejiang province. Soil samples were collected from vegetable fields, orchards, and paddy fields to measure their organic carbon, phosphorus, and other soil properties, from which we analyzed the relationship between soil organic carbon, phosphorus composition, reclamation duration, and land usage. A non-reclaimed soil was taken as the control. Result As reclamation time elapsed, soil pH decreased while total organic carbon (TOC), total phosphorus (TOP), and available phosphorus increased. Fifty years of reclamation led to a reduction in soil pH in Hangzhou Bay and Yueqing Bay by 1.72 to 2.36 and 1.14 to 2.24, respectively. This was accompanied by significant increases in organic carbon and TOP by 126.46% to 294.97% and 130.37% to 266.14%, and available phosphorus by 17.66% to 100.00% and 39.31% to 87.20%, respectively. The decrease in soil pH among different land usages was ranked in the order of wasteland > paddy field > orchard > vegetable field; the increase in soil organic carbon followed the order of paddy field > orchard > vegetable field > wasteland; and the increase in TOP and available phosphorus followed the order of wasteland < paddy field < orchard < vegetable land. Reclamation also significantly increased different forms of soil organic carbon. Over time, the ratio of free particulate organic carbon to organic carbon (fPOC/TOC) in micro-aggregates decreased initially and then gradually increased, while the ratio of occluded particulate organic carbon to organic carbon (oPOC/TOC) increased gradually. The ratio of mineral-associated organic carbon to organic carbon (MOC/TOC) initially increased significantly and then decreased slowly. Land usage had a notable impact on the MOC/TOC ratio, with paddy fields showing the highest influence, followed by orchards and vegetable fields. The impact of land usage on TOP and available phosphorus was more significant than reclamation time. Except for residual phosphorus and HCl-P, other forms of phosphorus increased with reclamation time. It was also found that with the increase in reclamation time, the fraction of residual phosphorus and HCl-P decreased, while the fraction of phosphorus in other forms increased. TOC and organic carbon in different forms exhibited a strong correlation, but no correlation was found between TOP and phosphorus. Conclusion Reclamation of the coastal saline soils results in continuous changes in composition and content of organic carbon and phosphorus, characterized by decreasing pH, increasing organic carbon and phosphorus. Land usage has a more substantial impact on the change in organic carbon and phosphorus than reclamation history. Growing rice promotes organic carbon sequestration, whereas vegetable cultivation enhances phosphorus accumulation. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alternate wetting and drying irrigation (IAWD) is one type of water-saving technology to repeatedly dry and re-flood the fields. However, the frequent alternate aerobic and anaerobic environment under IAWD has increased the reactive nitrogen gas emission in rice fields. Fortunately, biochar has been widely used to improve land productivity (including crop production, carbon sequestration, mitigation of GHG, and remediation of heavy metal pollution) in agricultural soil amendment. However, little information is available on the effects of biochar on NH3 volatilization, N2O emissions, and reactive nitrogen gas emissions in paddy rice systems, especially under IAWD. This study aims to explore the response mechanism of reactive nitrogen gas emissions to the biochar application under IAWD conditions. A two-year field split-plot experiment was conducted with the biochar application rates (0 and 20 t/hm² ) under two irrigation regimes (continuously flooded irrigation, ICF and IAWD). Two irrigation regimes were used as the main plots, whereas, two biochar additions were the subplots. Each plot was in the size of 3 m (width) × 6 m (length) that separated by the PVC barrier at a depth of 30 cm. in order to avoid the lateral flow of nutrients and water. The results showed that the IAWD increased yields by 1.7% to 5.1% (P>0.05), NH3 volatilization by 6.6% to 11.6%, and N2O emissions by 157.1% to 116.7%, compared with the ICF (P>0.05). Biochar addition at the rate of 20 t ha−1 significantly reduced the NH3 volatilization by 10.8% to 25.2% and N2O emissions by 21.6% to 24.2% (P>0.05). There was an increase in the yield by 0.2% to 12.5% and a reduction in the reactive nitrogen gas emissions by 6.1% to 11.7% in biochar combined with the IAWD, compared with the control (ICFB0). Furthermore, the inorganic nitrogen existed mainly in the form of NH4 + -N in the soil environment of rice fields, accounting for 80% to 90%. The IAWD had no significant impact on the soil NH4 + -N, compared with the ICF, whereas, a significant increase was found in the content of surface soil NO3 − -N by 50.3% to 74% and the oxidationreduction potential by 47.6% to 54.1% (P>0.05). Moreover, the biochar addition increased the soil NH4 + -N by 25.9% to 52.41% (P>0.05), and pH by 0.6% to 1%, compared with the biochar-free treatment. Principal component analysis showed a strong negative correlation between NH3 volatilization and soil NH4+ -N content, yield, and aboveground nitrogen accumulation. It indicated that the biochar addition significantly improved the soil adsorption capacity for the inorganic nitrogen, thereby reducing the NH3 volatilization losses and increasing aboveground nitrogen accumulation, ultimately leading to an increase in the yield. N2O emissions were strongly positively correlated with the oxidation-reduction potential and soil NO3 − -N. Therefore, the frequent alternate aerobic and anaerobic environment under IAWD increased the concentration of soil NO3 − -N and the oxidation-reduction potential, thereby increasing denitrification substrates and N2O emissions. Anyway, the biochar addition coupled with alternate wetting and drying can be expected to promote rice production with water saving, carbon sequestration and emission reduction, while reducing the environmental costs associated with the reactive nitrogen emissions in the paddy field. [ABSTRACT FROM AUTHOR]

This study aims to increase the fertilizer utilization rate for less fertilizer pollution in paddy fields. A side-deep fertilization device was developed to combine with the sliding-knife furrow opener and the pneumatic ejector for the liquid fertilizer atomizer using the side-deep fertilization and liquid fertilizer. The fertilizer was applied to the soil near the rice root zone. The structure of the inner cavity was designed for an air-liquid coaxial pneumatic ejector fertilizer atomizer. A full factorial soil bin test was conducted with the nozzle-throat distance, the mixer (throat) diameter, and air pressure. A systematic investigation was also made to explore the effects of each factor on the fertilizer discharge (liquid fertilizer mass flow rate) and air consumption (air flow). The findings indicate that the influencing factors of the liquid fertilizer mass flow rate were ranked in descending order of the mixer (throat) diameter, air pressure, and nozzle-throat distance. Similarly, the influencing factors of the air flow were ranked in descending order of the air pressure, nozzle-throat distance, and mixer (throat) diameter. The structural design was simulated and then optimized with the EDEM software. The Weighted Mark Method was used to comprehensively evaluate the simulation. The optimal performance was achieved in the sliding-knife furrow opener at various working rates when the sliding-cutting angle was 32.5˚ and the cutting-edge angle was 45˚. A soil bin test was implemented to verify the simulation. The measured and simulated traction resistance were 8.5, and 6.9 N, respectively, with a relative error of 18%, where the simulated soil disturbance area was 1965.6 cm², when the ditching depth of the sliding-knife furrow opener was 30 mm, and the forward speed was 1.2 m/s. Meanwhile, the measured and simulated traction resistance were 14.4 and 12.2 N, respectively, with a relative error of 15%, where the simulated soil disturbance area was 2137.2 cm² when the ditching depth was 50 mm and the forward velocity was 0.6m/s. When the ditching depth was 30mm and the forward speed was 1.2m/s, the standard deviation of fertilizer discharge was 0.2427g/s, the relative error to the maximum fertilizer discharge was 1.42%, and the relative error between the ditching depth and the fertilization depth was 4.4%, according to the soil bin performance test. When the ditching depth was 50 mm and the forward speed was 0.6 m/s, the standard deviation of fertilizer discharge was 0.479 6 g/s, the relative error to the maximum fertilizer discharge was 2.13%, and the relative error between the ditching depth and the fertilization depth was 2.1%. The finding can serve as promising guidance for the application of side-deep fertilization of liquid fertilizer in paddy fields. [ABSTRACT FROM AUTHOR]

Alternate wetting and drying irrigation (IAWD) is one types of water-saving technologies to repeatedly dry and re-flood the fields. However, the frequent alternate aerobic and anaerobic environment under IAWD has increased the reactive nitrogen gases emission in rice fields. Fortunately, biochar has been widely used to improve the land productivity (including the crop production, carbon sequestration, mitigation of GHG, and remediation of heavy metal pollution) in the agricultural soil amendment. However, little information is available on the effects of biochar on the NH3 volatilization, N2O emissions, and reactive nitrogen gas emissions in paddy rice systems, especially under IAWD. This study aims to explore the response mechanism of reactive nitrogen gas emissions to the biochar application under IAWD conditions. A two-year field split-plot experiment was conducted with the biochar application rates (0 and 20 t/hm²) under two irrigation regimes (continuously flooded irrigation, ICF and IAWD). Two irrigation regimes were used as the main plots, whereas, two biochar additions were the subplots. Each plot was in the size of 3 m (width) × 6 m (length) that separated by the PVC barrier at a depth of 30 cm. in order to avoid the lateral flow of nutrients and water. The results showed that the IAWD increased yields by 1.7% to 5.1% (P>0.05), NH3 volatilization 8.9%（only in 2020）, and N2O emissions by 105.0% to 115.0%, compared with the ICF (P<0.05). Biochar addition at the rate of 20 t/hm² was significantly reduced the NH3 volatilization by 8.7% to 20.5% and N2O emissions by 21.6% to 24.2% (P<0.05). There was an increase in the yield by 0.2% to 12.5% and a reduction in the reactive nitrogen gas emissions by 6.1% to 11.7% in biochar combined with the IAWD, compared with the control (ICFB0). Furthermore, the inorganic nitrogen existed mainly in the form of NH4+-N in the soil environment of rice field, accounting for 88.6% to 94.7%. The IAWD had no significant some impact on the soil NH4+-N, compared with the ICF, whereas, the significant increase was found in the content of surface soil NO3−-N by 50.3% to 74.0% and the oxidation-reduction potential by 47.6% to 54.1% (P<0.05). Moreover, the biochar addition increased the soil NH4+-N by 25.9% to 52.41% (P<0.05), and pH by 0.6% to 1.0%, compared with the biochar free treatment. Principal component analysis showed a strong negative correlation between NH3 volatilization and soil NH4+-N content, yield, and aboveground nitrogen accumulation. It indicated that the biochar addition was significantly improved the soil adsorption capacity for the inorganic nitrogen, thereby reducing the NH3 volatilization losses and increasing aboveground nitrogen accumulation, ultimately leading to increase the yield. N2O emissions were strongly positively correlated with the oxidation-reduction potential and soil NO3−-N. Therefore, the frequent alternate aerobic and anaerobic environment under IAWD increased the concentration of soil NO3−-N and the oxidation-reduction potential, thereby increasing denitrification substrates and N2O emissions. Anyway, the biochar addition coupled with alternate wetting and drying can be expected to promote the rice production with water saving, carbon sequestration and emission reduction, while reduce the environmental costs associated with the reactive nitrogen emissions in the paddy field. [ABSTRACT FROM AUTHOR]

Rice is one of the most significant crops in the world. Enough fertilizer supplied in the different growing period is necessary for the growth and yield of rice. Manual spreading is still the main way of paddy topdressing in China, leading to the inefficient and uneven application. A topdressing machine can be expected to reduce the labor intensity for the high productivity. Among them, the large spreading distance can be required for the mechanical spreading of fertilizer, in order to reduce the running times of the machine in paddy fields. Furthermore, the broken rate is the main influencing factor on the broadcasting distance. In this study, an experimental centrifugal disc fertilizer broadcaster with a guiding chute was designed for the parameter optimization of the machine, in order to increase the spreading range with the less breakage rate of the fertilizer. The broadcaster consisted of a revolving disc with the guiding blades, a feeding part, and a guiding chute. The spreading distance increased to combine the action of centrifugal force and airflow speed. The kinetic analysis of fertilizer grains was carried out to establish a functional relationship between spreading distance and fertilizer particle velocity. The structure and motion parameters of the device were determined, according to the models. The speed of the disc was determined as 850 r/min, the length of the guiding blade as 160 mm, and the distance between the feeding tube and the center of the disc as 90 mm. The fertilizer spreading was simulated using EDEM software. A systematic investigation was conducted to reveal the influence of structural parameters of fertilizer applicator guiding blade and the location of the chute on the initial speed of fertilizer particles. The guiding blade of the disc was determined to be the radial type. The internal airflow field of the fertilizer broadcaster was simulated using FLUENT, in order to clarify the influence of the fertilizer spreader guide tube on the fertilizer particle speed off the guiding chute. The structural parameters of the guide chute were optimized to be 200 mm of the length, 60 mm of the height, and 91.38° of the slope angle of guiding chute. The angle between the feeding tube and guiding chute was 53.75°. The fertilizer particles shared the higher speed at the leaving the guiding chute. The orthogonal experiment of four factors with three levels was conducted to evaluate the effects of blade number, blade form, blade height, and disc-chamber gap on the spreading distance and breakage rate of fertilizer grains. The optimization demonstrated that the distance was 16.95 m, and the fertilizer broken rate was 26.32%, which was 28.2 % lower than that of ordinary fertilizer broadcaster. As such, the fertilizer spreading distance increased by 5 m at the number of blades was 4, the blade type was radial, the height was 15 mm, and the disc-chamber gap was 25 mm. The finding can provide a strong reference for the development of fertilizer application device. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biochar is widely used as one type of soil amendment to enhance soil properties and carbon sequestration in croplands. But it is still unclear on the influence of rice straw biochar application on CH4 and N2O emissions from paddy fields, especially in Northeast China. The typical rice monoculture region is often used under the alternate regime of wetting and drying (IAWD) with the aging of biochar in soil. This study aims to further investigate the potential of biochar application in IAWD paddy fields. A split-plot field was designed with two irrigation regimes, two biochar additions, and three replications in 2019- 2021. Among them, the irrigation regimes (I) included continuous flooding irrigation (ICF) and IAWD. The sub-plots within each main plot were subjected to two biochar (B) additions (biochar-free control and 20 t ha-1 biochar, represented by B0 and B20, respectively). Prior to the experiment, the surface soil was first sampled in the rice fields and then air-dried to measure the basic physicochemical parameters of the soil. Biochar was applied one day before transplanting in 2019. After that, there was no additional biochar in 2020 and 2021. The opaque static chamber was used to collect the CH4 and N2O emissions over 3-4 days after topdressing, and 7-10 days between rice transplanting and harvesting. Gas samples were finally obtained to measure the CH4 and N2O concentration using gas chromatograph (Agilent 7890B, Agilent Technologies, Inc., USA). Results showed that the IAWD significantly reduced the CH4 emission by 63.03%-78.89%, global warming potential (GWP) by 62.02%-75.21%, greenhouse gas inventory (GHGI) by 62.31%-75.28%, compared with the ICF, although there was an increase in the N2O emission of 100%-122.67%. The B20 treatment reduced the CH4 emission by 21.99% in 2020, and 38.21% in 2021, whereas, there was an increase in the soil organic carbon by 24.03%-28.88%, and N2O emission by 28.26%-33.10% over three years. Moreover, biochar was used to inhibit the negative effect of IAWD on the increase of N2O emissions. A correlation analysis showed that there was a significant negative correlation in the cumulative CH4 emissions with the soil redox potential (Eh) value, and soil organic carbon (SOC), whereas a significant positive correlation was found with the soil temperature. There was a significant negative correlation between the cumulative N2O emission and soil temperature, whereas, a significant positive correlation was between the soil Eh value. A positive effect of rice production was found in the second and third years, although there was a slight decrease in the first year of biochar application. The main reason was that the early straw biochar was more alkaline with a limited effect. A synergy effect was found in the biochar adsorption emission reduction and slow release with the pH value to the normal, indicating the increasing production. Especially, the B20 treatment significantly reduced GWP by 37.50% and GHGI by 42.86% in 2021, whereas there was an increase of 11.02%, compared with the B0. The IAWD B20 treatment reduced the CH4 cumulative emissions by 83.78%, GWP by 77.98%, and GHGI by 78.95%, compared with the ICF B0. It infers that the biochar combined with IAWD can be used to effectively reduce the GWP and GHGI. Anyway, biochar can be expected to reduce carbon sequestration and CH4 and N2O emissions in paddy fields. The finding can also provide a strong theoretical reference to mitigate the CH4 and N2O emissions after the biochar application in rice fields. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

【Objective】The study aimed to address the conspicuous problem of excessive cadmium (Cd) in rice by developing and applying a nutrient inhibitor in the field to evaluate its effectiveness in reducing Cd uptake by rice and improving soil nutrients.【Method】One about 3.33 hm², high-risk, double-cropped rice field was selected as a demonstration area in each of three cities in the Pearl River Delta. The nutrient inhibitor was applied to the soil before rice seedling transplanting in both the early and late cropping seasons. Its impact on the mass fraction of Cd in brown rice from different rice varieties over both cropping seasons were studied and assessed, as well as its influence on soil properties. 【Result】The results showed that the nutrient inhibitor did not significantly impact the early or late cropping season rice yields in any of the three demonstration areas. However, it did reduce the mass fraction of Cd in brown rice, with reduction ranging from 8.43% to 72.5%. The nutrient inhibitor influenced soil properties differently. Compared to the control area, the nutrient inhibitor increased the pH of the soil in the double-cropped rice fields of the three demonstration areas by 0.10~0.42 units. The nutrient inhibitor increased the mass fractions of soil exchangeable calcium (Ca), magnesium (Mg), and available silicon (Si) which reached peak increases of 66.2%, 109%, and 53.0% respectively. However, the nutrient inhibitor did not noticeably change the mass fraction of soil hydrolytic nitrogen (N). In the demonstration area I and II, the inhibitor improved the mass fractions of available phosphorus (P) and available potassium (K) with peak increases of 78.3% and 24.6%, respectively, while in the demonstration area III, the inhibitor insignificantly changed them. The nutrient inhibitor significantly reduced the mass fraction of available Cd in the soil in the demonstration area I by 4.9%~7.3%, but it had no significant effect on that in the demonstration area II and III.【Conclusion】The nutrient inhibitor has ability to decrease the Cd accumulation in brown rice, and its impact on soil macro and moderate nutrients, and Cd bioavailability differentiates along with some conditions, while the inhibitor does not adversely affect soil properties or rice yields. Therefore, the nutrient inhibitor has the potential for safe and effective application to high-risk Cd-contaminated rice fields in the Pearl River Delta region. [ABSTRACT FROM AUTHOR]

Triflumezopyrim is a new type of mesoionic insecticide, which is mainly used for the control of piercing-sucking pests such as rice planthoppers and leafhoppers. It has good uptake and translocation ability. To clarify the uptake and translocation of triflumezopyrim in different paddy rice and provide a scientific basis for the reduction of its application and increase of its efficiency, Yangdao 6 and Nanjing 46 were used as the test paddy rice and the differences in the uptake and translocation of triflumezopyrim on them were explored by hydroponics and leaf soaking methods. The hydroponics treatment of paddy rice seedlings showed that the uptake capacity of triflumezopyrim by the roots of Yangdao 6 was stronger than that of Nanjing 46, but the ability of upward translocation was significantly lower than that of Nanjing 46. The results of the leaf soaking method showed that triflumezopyrim was not detected in the roots of two kinds of paddy rice, and the content of triflumezopyrim in leaves and stems of Yangdao 6 was significantly lower than that of Nanjing 46, but there was no significant difference in downward translocation ability. The results showed that triflumezopyrim could be absorbed by the roots and leaves of two kinds of paddy rice, and had an excellent ability for translocation to the top, but weak downward translocation ability. The top and down translocation capacity of triflumezopyrim in Nanjing 46 was better than that in Yangdao 6. [ABSTRACT FROM AUTHOR]