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Plastic film mulching increased the accumulation and human health risks of phthalate esters in wheat grains 全文
2019
Shi, Mei | Sun, Yingying | Wang, Zhaohui | He, Gang | Quan, Hanxiang | He, Hongxia
Plastic film mulching is a common practice to increase crop yield in dryland, while the wide use of plastic film has resulted in ubiquitous phthalate esters (PAEs) releasing into the soil. PAEs in soil could be taken up and accumulated by dietary intake of food crops such as wheat, thus imposing health risks to residents. In the present study, samples from a long-term location-fixed field experiment were examined to clarify the accumulation of PAEs in soil and wheat, and to assess the human health risks from PAEs via dietary intake of wheat grain under plastic film mulching cultivation in dryland. Results showed that concentrations of PAEs in grains from mulching plots ranged from 4.1 to 12.6 mg kg−1, which were significantly higher than those in the control group. There was a positive correlation for the PAE concentrations between wheat grains and field soils. Concentrations of PAEs in the soil were in the range of 1.8–3.5 mg kg−1 for the mulching treatment, and 0.9–2.7 mg kg−1 for the control group. Di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) were detected in all soil and grain samples, and DEHP was found to be the dominant PAE compound in grains. Based on DEHP concentrations in wheat grains, the values of carcinogenic risk for adults were higher than the recommended value 10−4. Results indicated that wheat grains from film mulching plots posed a considerable non-carcinogenic risk to residents, with children being the most sensitive resident group. Findings of this work call the attention to the potential pollution of grain crops growing in the plastic film mulching crop production systems.
显示更多 [+] 显示较少 [-]Effect of prothioconazole on the degradation of microplastics derived from mulching plastic film: Apparent change and interaction with heavy metals in soil 全文
2020
Li, Ruojia | Liu, Yi | Sheng, Yingfei | Xiang, Qingqing | Zhou, Ying | Cizdziel, James V.
Microplastic pollution is a major global environmental problem in both aquatic and terrestrial environments. Pesticides are frequently applied to agricultural soil to reduce the effects of pests on crops, but may also affect the degradation of plastics. In this study, we generated microplastics from polyethylene (PE) film and biodegradable poly(butylene adipate-co-terephthalate) (PBAT) film and determined (1) the effect of prothioconazole on degradation of the microplastics, and (2) the adsorption and release characteristics of heavy metals (Cr, Cu, As, Pb, Ba, and Sn) by the microplastics during degradation process. Changes of surface functional groups and morphologies were measured by FTIR and SEM, while metal concentrations were determined by ICPMS. Prothioconazole was found to promote plastic degradation. PBAT degraded faster and adsorbed more heavy metals from the soil than PE. Whether the microplastics adsorb or release heavy metals depended on the metal and their concentrations. Prothioconazole inhibited the adsorption of Cr, As, Pb and Ba by microplastics, promoted the adsorption of Cu, and had no significant effect for Sn. These results can help to assess the ecological risk of microplastic pollution from plastic mulch when combined with heavy metals.
显示更多 [+] 显示较少 [-]Agricultural plastic mulching as a source of microplastics in the terrestrial environment 全文
2020
Huang, Yi | Liu, Qin | Jia, Weiqian | Yan, Changrong | Wang, Jie
Plastic mulching is suspected to be a significant source of microplastics in terrestrial environments owing to its intensive application and improper disposal. However, there has been a comparative lack of studies examining this hypothesis. In this study, the occurrence of macroplastics in agricultural soils was investigated by analysing 384 soil samples collected from 19 provinces across China. Additionally, the abundance of microplastics was investigated in potential hotspots that have carried out plastic mulching for over 30 years. Macroplastic concentrations in the soil samples ranged from 0.1 to 324.5 kg/ha, with an average of 83.6 kg/ha; the concentrations were higher in western China than in eastern China. A highly significant linear correlation (R² = 0.61) was found between the consumption of mulching film and the plastic residue in soils, indicating plastic film mulching may be a major source of macroplastics. The abundances of microplastic particles increased over time in the locations where plastic mulching was continuously employed, with concentrations of 80.3 ± 49.3, 308 ± 138.1, and 1075.6 ± 346.8 pieces/kg soil in fields with 5, 15, and 24 y of continuous mulching, respectively. Fourier transform infrared analyses revealed that the composition of the microplastics matched that of the mulching films, suggesting the microplastic particles originated from the mulching films. These findings confirm that plastic mulching is an important source of macroplastic and microplastic contamination in terrestrial environments. Further studies to investigate the microplastic hazards in soils are thus necessary.
显示更多 [+] 显示较少 [-]Potential Nitrate Leaching Under Common Landscaping Plants 全文
2007
Amador, José A. | Hull, Richard J. | Patenaude, Erika L. | Bushoven, John T. | Görres, Josef H.
Studies on N losses from ornamental plantings - other than turf - are scant despite the ubiquity of these landscaping elements. We compared pore water NO₃ and extractable soil NO₃ and NH₄ in areas with turf, areas with seven different types of ornamental landscape plantings, and a native woodland. Turf areas received annual N inputs of ~48 kg ha-¹ and annual flowers received ~24 kg N ha-¹ at the time of planting. None of the other areas were fertilized during the course of the study. Data were collected on 23 occasions between June 2002 and November 2003. Pore water NO₃ concentrations at a 60-cm depth - based on pooled data - were highest (1.4 to 7.8 mg NO₃-N l-¹) under ground covers, unplanted-mulched areas, turf, deciduous trees, and evergreen trees, with no differences among these vegetation types. Lower values were observed under woodlands, annual and perennial flowers, and evergreen and deciduous shrubs. Pore water NO₃ concentrations exceeded the drinking water regulatory limit of 10 mg NO₃-N l-¹ under ground covers, turf and unplanted-mulched areas in 39, 20 and 10% of samples, respectively. Leaching losses of NO₃-N over 18 months ranged from 0.17 kg N ha-¹ in the woodlands to 34.97 kg N ha-¹ under ground covers. Annual NO₃ losses under unplanted-mulched areas and ground covers were approximately twice the average N input (10 kg N ha-¹ year-¹) from atmospheric deposition. Extractable NO₃ in woodland soils (0.5 μg NO₃-N g-¹) was lower than for all other vegetation types (3.1-7.8 μg NO₃-N g-¹). Extractable NH₄ levels were highest in woodlands, deciduous trees, and annual flowers (6.7-10.1 μg NH₄-N g-¹). Most vegetation types appear to act as net N sinks relative to atmospheric inputs, whereas unplanted-mulched areas and areas planted with ground covers act as net sources of NO₃ to groundwater.
显示更多 [+] 显示较少 [-]Comparative Analysis of Mulching and Weed Management Practices on Nutrient and Weed Dynamics of Kharif Sorghum (Sorghum bicolor L.) 全文
2024
Abhinav Thakur, Hina Upadhyay, Lalit Saini, Tarun Sharma and Himanshu Saini
The present field study was conducted to evaluate the effects of mulching and weed control methods on the nutrient and weed dynamics of Kharif Sorghum. The research was conducted in the Agronomy farm of Lovely Professional University in Phagwara, Punjab, during the summer of 2023. The experiment utilized a randomized block design with three replications. A total of six treatments were used, each with different amounts of treatment applied to assess the effects on the growth, yield, and weed characteristics of sorghum. The growth metrics, including plant height, leaf count, stem circumference, leaf area index, and chlorophyll content, saw significant improvement as a result of the amplified influence of mulching and weed management. Treatment T1, which excluded weeds, yielded the greatest plant height (134.69 cm), number of leaves (8.73), stem girth (10.14 cm) at harvest, leaf area index (7.78), and chlorophyll content (53.74) at 90 days after sowing (DAS). The T1 treatment, which was free of weeds, had the most favorable production characteristics. The grain yield was recorded at 2.15 t.ha-1, the straw yield at 4.59 t.ha-1, and the harvest index at 22.54%. The highest protein concentration was observed as 10.84% in T1 (Weed free) and 10.73% in T2 (Sugarcane trash). In addition, the characteristics of the weed, including the number of weeds, the effectiveness of weed management, and the weight of the weeds, were shown to be highest in dicots at 120 days after sowing (DAS). Treatment T1, which involved the complete removal of weeds, exhibited no weed population and achieved the maximum level of weed control effectiveness and dry weight. The study’s findings indicated that the use of T1 (Weed-free) treatment had a substantial influence on different growth, yield, and weed characteristics. Effective management of essential inputs, such as cultivation, fertilizers, and weed management, is vital for improving overall productivity and stability
显示更多 [+] 显示较少 [-]Year-round film mulching system with monitored fertilization management improve grain yield and water and nitrogen use efficiencies of winter wheat in the dryland of the Loess Plateau, China 全文
2019
Li, Tingliang | Xie, Yinghe | Gao, Zhiqiang | Hong, Jianping | Li, Li | Meng, Huisheng | Ma, Hongmei | Jia, Junxiang
Year-round film mulching in winter wheat field facilitates rainwater storage in summer fallow period and reduces water evaporation in growing reason, and then increases water use efficiency in the dryland of the Loess Plateau, China. Optimized fertilization further promotes fertilizer utilization efficiencies. In this study, plastic film mulching was extended from plant growth season to summer fallow, and fertilizers were applied by monitoring soil nutrient availability. Field trials were conducted in the dryland of the Loess Plateau over 4 years by using four types of cultivation to investigate the effects of year-round plastic film mulching with monitored fertilization on utilization efficiencies of rainwater and nitrogen (N), and winter wheat yield. The four types of cultivation were farmer practice (FP), ridge-furrow with plastic film mulching system plus conventional fertilization(RPCF), ridge-furrow with plastic film mulching system plus monitored fertilization (RPFM), and flat soil surface with plastic film mulching system plus monitored fertilization (FPFM). Our results indicate that the average yield of winter wheat in RPFM and FPFM treatments was 4491 kg ha⁻¹. Compared with FP treatment, the combined effects of monitored fertilization and film mulching(RPFM and FPFM treatments) could increase grain yield in the range of 24.7 to 42.1%. The film mulching extended to the fallow season increased the water storage in 2 m depth of soil profile, and the amount of soil water storage in the summer fallow period increased by 27 to 30% in FPFM treatment than FP treatment. After 4-year consecutive planting of wheat, the accumulation of nitrate-N in 2 m soil reached 277 kg·ha⁻¹ in the FP treatment, which is 87.7% higher than of the level at the beginning of the experiment. Seventy-five percent of nitrate-N was distributed in the soil layer of 0–120 cm. In addition, the residual nitrate-N showed downward leaching with rainfall during the experiment. The RPFM and FPFM treatments reduced the apparent loss and residual levels of soil N, whereas increased its apparent mineralization compared with FP treatment. The FPFM treatment exhibited a greater utilization of residual nitrate-N from previous years and showed a higher amount of the mineralized N from soil organic matter, therefore leading to a relatively high apparent utilization rate of N (56.7%). Considering both grain yield production and utilization efficiencies of water and N, FPFM with year-round mulching was the most effective cultivation measure for winter wheat in the Loess Plateau.
显示更多 [+] 显示较少 [-]Optimum ridge-to-furrow ratio in ridge-furrow mulching systems for improving water conservation in maize (Zea may L.) production 全文
2017
Li, Weiwei | Wen, Xiaoxia | Han, Juan | Liu, Yang | Wu, Wei | Liao, Yuncheng
Water-saving cultivation techniques have been attracting increased attention worldwide. Ridge-furrow mulching system (RFMS), as a prospective rainwater harvesting system, has been widely adopted in arid and semi-arid areas. Field experiments were conducted in 2014 and 2015 to compare soil water storage, soil temperature, maize yield, and water use efficiency (WUE) among different ridge/furrow width arrangements in RFMS comprised of three different ridge/furrow ratios, i.e., 40:70 cm (RFMS40), 55:55 cm (RFMS55), and 70:40 cm (RFMS70) and conventional flat planting (CK, without mulching). All these four planting patterns had the same planting density. The RFMS technique not only increased soil temperature of the ridge but also improved soil moisture of the furrow when compared with CK. These positive effects were intensified with increasing ridge/furrow ratio in RFMS. This improvement in RFMS resulted in more stable and earlier seedling establishment. Maize yields were increased by 26.1, 36.4, and 50.3% under RFMS40, RFMS55, and RFMS70 treatments, respectively, when compared with CK across both years. RFMS did not decrease the evapotranspiration significantly, compared with CK. Eventually, WUE were enhanced by 25.7, 38.7, and 53.9% in RFMS40, RFMS55, and RFMS70, respectively, compared with CK. Taken together, our results suggest that increasing ratio of ridge to furrow in the case of RFMS70, can be recommended as high-yielding cultivation pattern for promoting precipitation use efficiency in the rain-fed semi-arid areas.
显示更多 [+] 显示较少 [-]Biology and management of two important Conyza weeds: a global review 全文
2016
Bajwa, Ali Ahsan | Sadia, Sehrish | Ali, Hafiz Haider | Jabran, Khawar | Peerzada, Arslan Masood | Chauhan, Bhagirath Singh
Weed management is one of the prime concerns for sustainable crop production. Conyza bonariensis and Conyza canadensis are two of the most problematic, noxious, invasive and widespread weeds in modern-day agriculture. The biology, ecology and interference of C. bonariensis and C. canadensis have been reviewed here to highlight pragmatic management options. Both these species share a unique set of biological features, which enables them to invade and adapt a wide range of environmental conditions. Distinct reproductive biology and an efficient seed dispersal mechanism help these species to spread rapidly. Ability to interfere strongly and to host crop pests makes these two species worst weeds of cropping systems. These weed species cause 28–68 % yield loss in important field crops such as soybean and cotton every year. These weeds are more prevalent in no-till systems and, thus, becoming a major issue in conservation agriculture. Cultural practices such as crop rotations, seed rate manipulation, mulching, inter-row tillage and narrow row spacing may provide an effective control of these species. However, such methods are not feasible and applicable under all types of conditions. Different herbicides also provide a varying degree of control depending on crop, agronomic practices, herbicide dose, application time and season. However, both these species have evolved resistance against multiple herbicides, including glyphosate and paraquat. The use of alternative herbicides and integrated management strategies may provide better control of herbicide-resistant C. bonariensis and C. canadensis. Management plans based on the eco-biological interactions of these species may prove sustainable in the future.
显示更多 [+] 显示较少 [-]Cultivation modes and deficit irrigation strategies to improve 13C carbon isotope, photosynthesis, and winter wheat productivity in semi-arid regions 全文
2019
Shahzād, ʻAlī | Xu, Yueyue | Ma, Xiangcheng | Henchiri, Malak | Cai, Tie | Ren, Xiaolong | Zhang, Jiahua | Jia, Zhikuan
Determining the effect of ridge-furrow cultivation mode on ¹³C carbon isotope discrimination, photosynthetic capacity, and leaf gas exchange characteristics of winter wheat leaves will help to increase wheat production. To verify these effects of cultivation modes with deficit irrigation will provide scientific basis for determining water-saving strategy. Therefore, a mobile rainproof shelter was used to explore the potential benefit of two cultivation modes: (1) the ridge-furrow (RF) precipitation system and (2) traditional flat planting (TF) with two deficit irrigation levels (150, 75 mm) and three precipitation levels (275 mm, 200 mm, 125 mm) were tested in this study. Plastic film mulching on ridges had significant effects on rainwater collection and improved soil water retention. Analysis of the light-response curve showed that RF2₁₅₀ treatment significantly increased flag leaf net photosynthetic rate (Pₙ), stomatal conductance (Gₛ), intercellular CO₂ concentration (Cᵢ), transpiration rate (Tᵣ), leaf WUE, and total contents of chlorophyll ab of wheat at flowering stage than that of TF planting. The RF system significantly increases maximum net photosynthetic rate (Pₙₘₐₓ) (16.2%), light saturation points (LSP) (6.7%), and Pₙ under CO₂-response curves compared to the TF cultivation across the two irrigation and three simulated rainfall levels. The RF system significantly increased Δ¹³C (0.7%) and caused a notable increase in the intercellular to ambient CO₂ concentration ratio (7.6%), dry matter translocation (54.9%), and grain yield plant⁻¹ (19%) compared to the TF planting. Furthermore, Δ¹³C was significantly positively correlated with Pₙ, Gₛ, Cᵢ/Cₐ, Cᵢ, Tᵣ, Pₙₘₐₓ, LSP, and grain yield. This study suggested that the RF2₁₅₀ treatment was the best water-saving technique because it increased soil water content, Δ¹³C, biomass, grain yield, and leaf WUE.
显示更多 [+] 显示较少 [-]Effects of rice straw mulching on N2O emissions and maize productivity in a rain-fed upland 全文
2018
Wu, Xiaohong | Wang, Wei | Xie, XiaoLi | Yin, ChunMei | Hou, HaiJun
In the hilly areas of southern China, uplands and paddies are located adjacent to each other. Using rice straw as mulch for upland soil may improve crop production and partially replace chemical fertilizers, which may mitigate N₂O emissions. A field experiment was conducted to investigate the potential of rice straw mulching for mitigating N₂O emissions and increasing crop production. The treatments included no mulching (CK), 5000 kg ha⁻¹ of straw mulching (SM5), and 10,000 kg ha⁻¹ of straw mulching (SM10). Moreover, all the treatments received equivalent amounts of nitrogen, phosphorus, and potassium from chemical fertilizers plus rice straw. Relative to CK, cumulative N₂O emissions decreased by 23.1 and 33.5% with SM5 and SM10, respectively. Significant positive correlations were observed between N₂O fluxes and soil water-filled pore space (WPFS) (r ² = 0.495, P < 0.05) and between seasonal cumulative N₂O fluxes and the chemical N fertilization rate (r ² = 0.814, P < 0.05). These findings indicate that soil WPFS was the key environmental factor in N₂O emissions and that the substitution of chemical nitrogen fertilizer with rice straw was the main driver of N₂O mitigation. Relative to CK, the maize yield increased by 16.5 and 29.6% with SM5 and SM10, respectively, which can be attributed primarily to the increases in soil moisture. The chemical fertilizer input could be decreased and N₂O emissions could be mitigated through straw mulching, while achieving improved crop yield. This management strategy has great potential, and this study provides an important reference for low-carbon agriculture.
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