Crop Growth Period Research Articles

Crop acreage and yield mapping of groundnut crop in erstwhile Mahabubnagar District using RS and GIS

An investigation was carried in the erstwhile Mahabubnagar district of Telangana during rabi 2019-20 aiming the estimation of groundnut crop acreage and yield. The crop area was estimated using the satellite images of Landsat-8-OLI sensor from September to February covering the entire crop growth period by performing an unsupervised image classification technique with 300 classes, 300 iterations and a convergence threshold of 0.99. The groundnut yield was estimated by developing the regression equation using crop-cut yield data and NDVI values of the corresponding GPS locations. The crop area was estimated to be 57,865 ha with producer’s and user’s accuracy of 100 and 90% respectively, and a relative deviation of 28.6% when compared with actual ground estimates of the Department of agriculture. The crop yields were estimated with an R2 value of 0.71 and a correlation coefficient of 0.87

Influence of Nano Nitrogen and Phosphorus Fertilizer on Yield and Nutrient Content of Maize (Zea mays L.)

The study entitled, “Influence of nano nitrogen and phosphorus fertilizer on yield and nutrient content of maize (Zea mays L.)” was undertaken by conducting a laboratory experiment of synthesis and characterization of nitrogen and phosphorus nano-fertilizer and a field experiment at Regional Research Station, Anand Agricultural University, Anand (Gujarat) during summer and kharif seasons of the year 2021. The field experiment was laid out in Randomized Block Design comprising fourteen treatments of T1[Control(No NPK)], T2[100% RDF (150 N-60 P-0 K kg ha-1)], T3[75% RDF + Nano N and P through foliar application (1000 ppm)], T4[75% RDF + Nano N and P through foliar application (2000 ppm)], T5[75% RDF + Nano N and P through foliar application (3000 ppm)], T6[50% RDF + Nano N and P through foliar application (1000 ppm)], T7[50% RDF + Nano N and P through foliar application (2000 ppm)], T8[50 % RDF + Nano N and P through foliar application (3000 ppm)], T9 [25% RDF + Nano N and P through foliar application (1000 ppm)] and T10[25% RDF.
 + Nano N and P through foliar application (2000 ppm)], T11[25% RDF + Nano N and P through foliar application (3000 ppm)], T12[ Seed treatment Nano N and P + Nano N and P through foliar application (1000 ppm)], T13[ Seed treatment Nano N and P + Nano N and P through foliar application (2000 ppm)], T14[ Seed treatment Nano N and P + Nano N and P through foliar application (3000 ppm)]. In case of seed treatment with nitrogen and phosphorus NPs, seeds were soaked in nitrogen and phosphorus NPs suspension of 1000 ppm for 2 hours. The foliar application was made during crop growth period with three sprays at 15, 30 and 60 DAS of the crop. The treatments were tested against the control. Signficantly higher grain yield, straw yield, nitrogen and phosphorus content in maize was recorded was achieved under application of T4- 75% RDF + Nano N and P through foliar application (2000 ppm) during both seasons.

Assessing long-term impacts of cover crops on soil organic carbon in the central US Midwestern agroecosystems.

Cover crops have been reported as one of the most effective practices to increase soil organic carbon (SOC) for agroecosystems. Impacts of cover crops on SOC change vary depending on soil properties, climate, and management practices, but it remains unclear how these control factors affect SOC benefits from cover crops, as well as which management practices can maximize SOC benefits. To address these questions, we used an advanced process-based agroecosystem model, ecosys, to assess the impacts of winter cover cropping on SOC accumulation under different environmental and management conditions. We aimed to answer the following questions: (1) To what extent do cover crops benefit SOC accumulation, and how do SOC benefits from cover crops vary with different factors (i.e., initial soil properties, cover crop types, climate during the cover crop growth period, and cover crop planting and terminating time)? (2) How can we enhance SOC benefits from cover crops under different cover crop management options? Specifically, we first calibrated and validated the ecosys model at two long-term field experiment sites with SOC measurements in Illinois. We then applied the ecosys model to six cover crop field experiment sites spanning across Illinois to assess the impacts of different factors on SOC accumulation. Our modeling results revealed the following findings: (1) Growing cover crops can bring SOC benefits by 0.33 ± 0.06 MgC ha-1 year-1 in six cover crop field experiment sites across Illinois, and the SOC benefits are species specific to legume and non-legume cover crops. (2) Initial SOC stocks and clay contents had overall small influences on SOC benefits from cover crops. During the cover crop growth period (i.e., winter and spring in the US Midwest), high temperature increased SOC benefits from cover crops, while the impacts from larger precipitation on SOC benefits varied field by field. (3) The SOC benefits from cover crops can be maximized by optimizing cover crop management practices (e.g., selecting cover crop types and controlling cover crop growth period) for the US Midwestern maize-soybean rotation system. Finally, we discussed the economic and policy implications of adopting cover crops in the US Midwest, including that current economic incentives to grow cover crops may not be sufficient to cover costs. This study systematically assessed cover crop impacts for SOC change in the US Midwest context, while also demonstrating that the ecosys model, with rigorous validation using field experiment data, can be an effective tool to guide the adaptive management of cover crops and quantify SOC benefits from cover crops. The study thus provides practical tools and insights for practitioners and policy-makers to design cover crop related government agricultural policies and incentive programs for farmers and agri-food related industries.

Effect of Rational Fertilizer for Eggplants on Nitrogen and Phosphorus Pollutants in Agricultural Water Bodies

Excessive fertilizer application in the cropping industry leads to excessive nitrogen and phosphorus in surrounding water bodies, which causes farmers to increase economic cost and damage the environment. To address the problem, we built a crop-soil runoff soil column test system, setting eight fertilizer application levels for eggplants. Then, crop yield, soil fertility and pollutant concentrations in the receiving water bodies were measured. The process of fertilizer application on the water quality of surrounding receiving water bodies and the rationality of fertilizer application were analyzed. The results showed that crop yield, soil fertility, and pollutant concentrations in the receiving water increased with the increase in fertilizer application. The crop yield stabilized when the fertilizer application amount was higher than 0.12 kg/m2; the concentrations of total nitrogen (TN) and total phosphorus (TP) in the water increased significantly with the increase in fertilizer application, where particulate nitrogen (PN) and organic phosphorus (OP) were the key pollutants. In addition, crop growth had an interception effect on pollutant migration. The concentration of pollutants in the water was significantly lower in the late crop growth period (after flowering) than in the early. The crop had the best interception effect on pollutants when the fertilizer application was 0.12 kg/m2. The concentrations of TN and TP in the water were 29.7% and 22.3% after the flowering period, being lower than those before the flowering period. Therefore, a reasonable value of 0.12 kg/m2 is recommended for fertilizer application in this article. It can provide a reference for the fertilization system of eggplant planting in North China and theoretical support for the realization of clean production in small rural watershed planting.

Impact of weather parameters on maize agroecosystem and adaptation strategies under changing climatic conditions: A review: Sustainable and climate-resilient adaptation strategies in maize agroecosystem

Change in precipitation patterns and increase in the frequency and intensity of extreme weather events (high temperatures and heat waves) harm crop productivity. As per the future prediction, the temperature may increase by 2.5 0C by 2050 and by 2-30 C by the end of the century. The present review evaluates the impact of a rise and fall in temperature, solar radiation, and CO2 on the productivity of maize and other crops. Agronomic management practices during the crop growth period of selecting crop cultivars, date of sowing, plant population, dosage, timing, and methods of application of inputs are influenced by temperature, rainfall, solar radiation, and CO2 concentration in the atmosphere. Overall crop productivity will reduce by 50.9 % in wheat in the USA, 46% in maize in China,17% in cotton in India, and 30% in sugarcane in India. Changing the sowing date and adopting improved early and short-duration varieties of corn and other crops are becoming significant under low-cost adoption technologies to mitigate climate change. Info Crop-SORGHUM simulation model predicts that change in the sowing date of a variety in sorghum reduces the impact of climate change and vulnerability to 1- 2 % by 2020, 3-8 % by 2050, and 4-9% by 2080. The review highlights the impact of heat stress and drought on soil processes, and overall soil health. The authors conclude to implement climate adoption technologies based on Agriculture 4.0 to sustain crop production globally.

Assessment of Method and Application Schedule of Fertilizer N and K on Growth and Productivity of Summer Planted Sugarcane Crop (Saccharum officinarum L.) under Wide Spacing

Present investigation was carried out at Regional Research Station, Uchani (Karnal) of CCS Haryana Agricultural University, Hisar, India during 2020-21 to assess the effect of method and schedule of fertilizer application on growth, yield attributes and cane yield of summer planted sugarcane (Saccharum officinarum L.) crop under wide spacing (120 cm). The experiment was arranged in split plot design with two methods of fertilizer application (B1-broadcasting and B2- band placement) as main plot treatments and four sub plot treatments which include application of recommended dose of N and K fertilizer (RDF) in different number of splits at different no. of days after planting (DAP) i.e. T1 (five splits), T2 (six splits), T3 (seven splits) and T4 (three splits). Results concluded that majority of growth parameters, yield attributes and cane yield were significantly affected by both main and sub plot treatments at different stages of crop growth period. Treatment B2 registered significantly higher tiller population (110.59 and102.68 000 ha-1 at 60 and 120 DAP respectively), plant height (91.16, 141.18, 400.12 and 412.13 cm at 60, 120, 180 and 240 DAP respectively), no. of millable canes (NMC) (100.79 and 96.58 000 ha-1 in mid-September and at harvesting respectively) cane length (234.64 cm at harvesting) and cane yield (93.16 t ha-1)compared to B1. Among sub plot treatments, T1 outperformed all the other treatments in terms of growth, yield attributes and cane yield. Treatment T1 registered maximum plant height (150.43, 411.0 and 427.45 cm at 120, 180 and 240 DAP respectively), tiller population (104.72 000 ha-1 at 120 DAP), NMC (102.06 and 95.20 000 ha-1 in mid-September and at harvesting respectively) and cane yield (94.83 t ha-1). Germination percentage, cane girth, no. of internodes per cane and length of internodes was not significantly affected either by main or sub plot treatments.

Improvement of Water and Nitrogen Use Efficiencies by Alternative Cropping Systems Based on a Model Approach.

The conventional double cropping system of winter wheat and summer maize (WW-SUM) in the North China Plain (NCP) consumes a large amount of water and chemical fertilizer, threatening the sustainable development of agriculture in this region. This study was based on a three-year field experiment of different cropping systems (2H1Y-two harvests in one year; 3H2Y-three harvests in two years; and 1H1Y-one harvest in one year). The 2H1Y system had three irrigation-fertilization practices (FP-farmer's practice; RI-reduced input; and WQ-Wuqiao pattern in Wuqiao County, Hebei Province). A soil-crop system model (WHCNS-soil water heat carbon nitrogen simulator) was used to quantify the effects of different cropping systems on water and nitrogen use efficiencies (WUE and NUE, respectively), and to explore the trade-offs between crop yields and environmental impacts. The results showed that annual yield, water consumption, and the WUE of 2H1Y were higher than those of the 3H2Y and 1H1Y systems. However, local precipitation during the period of crop growth could only meet 65%, 76%, and 91% of total water consumption for the 2H1Y, 3H2Y and 1H1Y systems, respectively. Nearly 65% of irrigation water (groundwater) was used in the period of wheat growth that contributed to almost 40% of the annual yield. Among the three patterns of the 2H1Y system, the order of the WUE was 2H1Y_RI > 2H1Y_WQ > 2H1Y_FP. Compared to 2H1Y_FP, the total fertilizer N application rates in 2H1Y_WQ, 2H1Y_RI, and 3H2Y were reduced by 25%, 65%, and 74%, respectively. The 3H2Y system had the highest NUE of 34.3 kg kg-1, 54% greater than the 2H1Y_FP system (22.2 kg kg-1). Moreover, the 3H2Y system obviously reduced nitrate leaching and gaseous N loss when compared with the other two systems. The order of total N loss of different cropping systems was 2H1Y (261 kg N ha-1) > 1H1Y (78 kg N ha-1) > 3H2Y (70 kg N ha-1). Considering the agronomic and environmental effects as well as economic benefits, the 3H2Y cropping system with optimal irrigation and fertilization would be a promising cropping system in the NCP that could achieve the balance between crop yield and the sustainable use of groundwater and N fertilizer.

Spatiotemporal variation of irrigation water requirements for grain crops under climate change in Northwest China.

Clarifying the spatiotemporal variation of crop irrigation water requirement (IWR) under the background of climate change is an essential basis for water resource management, determining the irrigation quota and adjusting the planting structure. Using 61years of climate data from 205 stations in Northwest China, this study investigated the spatiotemporal variations of climatic factors and IWR during the growth period of five main grain crops (spring wheat, winter wheat, spring maize, summer maize, and rice) and explored the dominant climatic driving factors of IWR variation. Results showed that (1) the IWR of grain crops showed distinct differences. Rice was the highest water consumption crop (mean of 753.78mm), and summer maize was the lowest (mean of 452.90mm). (2) The variation trends and average values of IWR of different grain crops have spatial heterogeneity across Northwest China. For most crops, high values and increasing trends of IWR were mainly located in eastern Xinjiang, western Gansu, and western Inner Mongolia. (3) Tmax (maximum temperature), Tmin (minimum temperature), and Peff (effective precipitation) showed an increasing trend during the growth period of each grain crop, while U10 (wind speed at 10m height), SD (solar radiation), and RH (relative humidity) presented decreasing trends. (4) SD, Tmax, and U10 promoted the increase of grain crops' IWR, while Peff and RH inhibited it. The impacts of climatic factors on the grain crop IWR differed among different regions. Peff was the most influential factor to the IWR of all grain crops in most areas. Therefore, under the premise of a significant increase in T and uncertain precipitation mode in the future, it is urgent to take effective water-saving measures according to the irrigation needs of the region. To cope with the adverse impact of climate change on the sustainable development of agriculture in the northwest dry area, to ensure regional and national food security.

Effects of solarisation combined with compost on soil pathogens and the microbial community in a spinach cropping system

This study compares the effects of solarization combined with compost (72% vineyard prunings and 28% leek residues) (CAS) versus solarization (NAS) in soils used for intensive spinach cultivation in the Mediterranean area. The objective was to study the beneficial effects of the compost on the soil microbial community, soil fertility and soil functionality related to C and N cycling during solarization, during the spinach crop growth period and after harvesting. CAS did increase soil fertility and microbial activity, in addition, CAS increased the microbial alpha diversity in the soil to a greater extent than NAS, and the Principal Coordinate Analysis (PCoA) of the beta diversity in the soil revealed changes in the bacterial and fungal community at the different sampling times, except after the plastic was lifted. During solarization and after harvesting, different beneficial bacteria and fungi related to C and N cycling were more abundant in CAS than in NAS, in the same way as the genera involved in plant defense and plant growth (Pseudomonas, Sphingomonas, Bacillus, Thermomyces, Streptomyces, NMD1 or Nitrospira). CAS also had a notable effect on the abundance of predictive genes involved in the C and N cycles. The functional genes showed their lowest activity level a week after covering the soil with plastic, but they increased after lifting the plastic and after harvesting. Compared to NAS, CAS also showed higher N2-fixation and greater conversion of N2O to N2. Moreover, the abundance of several predictive genes involved in hemicellulose, lignin and cellulose degradation suggested that CAS produced an increase in nutritional availability. From this study, it can be concluded that the combination of solarization and compost increased soil fertility, microbial activity, microbial diversity and functionality. Compost could provide added value by stimulating the microbiological community in the soil until harvest.

基于SWAT模型的图们江流域蓝绿水资源供需平衡分析

PDF HTML阅读 XML下载 导出引用 引用提醒 基于SWAT模型的图们江流域蓝绿水资源供需平衡分析 DOI: 10.5846/stxb202112173586 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目(2019YFC0409104035679); 国家自然科学基金项目(42061042) Analysis of blue and green water scarcity based on SWAT model in the Tumen River Basin Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:随着经济快速发展和工农业各类用水量大幅增加,对河流的开发程度随之加强,流域水资源可持续利用受到不利影响。从蓝绿水视角出发,基于SWAT模型量化了图们江流域2015-2020年不同时间尺度下的蓝绿水资源并探讨了研究区水资源供需平衡情况。结果表明:研究时段内流域蓝绿水资源均具有明显的季节特征,年均蓝绿水资源量为117.16 亿m3,其中蓝水资源量30.14 亿m3,绿水资源量87.02 亿m3,绿水占水资源量的74.27%。以年为尺度,蓝水资源供需评估指数＞1,可利用蓝水资源量基本不能满足其需求量,降水少的年份蓝水资源供需矛盾突出,而绿水资源可以达到供需平衡,其供需评估指数集中在0.1-0.2之间。在月尺度分析中研究区蓝水供需评估指数出现极端值的频率较高,表明该地区蓝水供需不平衡,尤其是可利用蓝水资源一般在每年的7-8月才较为丰富,而蓝水需求用水集中分布于作物生长期,导致蓝水供应与蓝水需求在时间分配上不均衡,且在实际水资源分配中忽略了生态用水;月尺度绿水供需评估指数集中在0.1-0.4之间,有明显的季节变化特征,整体上绿水资源供需平衡安全性较高。 Abstract:With the rapid economic development, the amount of water used for industry and agriculture has significantly increased, most rivers were blind developed and affected the sustainable utilization of water resources. This study quantified water resources from the perspective of blue and green water. The Soil and Water Assessment Tool (SWAT) model was used to simulate the natural runoff in the Tumen River Basin from 2015 to 2020, quantitatively analyzed the change trend of blue water and green water resources at different time scales, and discussed the balance of water supply and demand in the study area. The results showed that the blue and green water resources of the Tumen River Basin presented significantly seasonal characteristics from 2015 to 2020. The average annual amount of blue and green water resources was 11.716 billion m3. The blue and green water resources of the study river basin from 2015 to 2020 were 3.014 billion m3/a and 8.702 billion m3/a, respectively. The study area had different degrees of water scarcities in different time scales. At the annual scale, the supply and demand index of blue water resource was greater than 1, which indicated the supply of blue water basically could not satisfy the demand. The imbalance degree of supply and demand of blue water resource was evident in less precipitation years. In contrast, the balance of supply and demand of green water resource was relatively stable, the index concentrated between 0.1 and 0.2. At the monthly scale, the blue water supply and demand balance index put up high frequency of extreme value, illustrated there was an imbalance appearance between the blue water supply and demand in this region. Especially the blue water availability in annual July to August had the maximum values. However, the blue water withdrawal intensively distributed in the crop growth period, there had a time mismatch between the supply and demand of blue water in the river basin. Moreover, the ecological water was neglected in actual water resources allocation. The monthly green water supply and demand index concentrated between 0.1 and 0.4, with prominently seasonal variation characteristics. Overall, the balance between the supply and demand of green water resource was relatively safe. 参考文献 相似文献 引证文献

Dynamic UAV Phenotyping for Rice Disease Resistance Analysis Based on Multisource Data.

Bacterial blight poses a threat to rice production and food security, which can be controlled through large-scale breeding efforts toward resistant cultivars. Unmanned aerial vehicle (UAV) remote sensing provides an alternative means for the infield phenotype evaluation of crop disease resistance to relatively time-consuming and laborious traditional methods. However, the quality of data acquired by UAV can be affected by several factors such as weather, crop growth period, and geographical location, which can limit their utility for the detection of crop disease and resistant phenotypes. Therefore, a more effective use of UAV data for crop disease phenotype analysis is required. In this paper, we used time series UAV remote sensing data together with accumulated temperature data to train the rice bacterial blight severity evaluation model. The best results obtained with the predictive model showed an R p 2 of 0.86 with an RMSEp of 0.65. Moreover, model updating strategy was used to explore the scalability of the established model in different geographical locations. Twenty percent of transferred data for model training was useful for the evaluation of disease severity over different sites. In addition, the method for phenotypic analysis of rice disease we built here was combined with quantitative trait loci (QTL) analysis to identify resistance QTL in genetic populations at different growth stages. Three new QTLs were identified, and QTLs identified at different growth stages were inconsistent. QTL analysis combined with UAV high-throughput phenotyping provides new ideas for accelerating disease resistance breeding.

Влияние основных приемов и способов возделывания ярового ячменя на площадь ассимиляционной поверхности и индекс листовой поверхности посевов в почвенно-климатических условиях Курской области

Purpose: to determine the influence of the cultivar, seeding rate and application of mineral fertilizers when cultivating spring barley on the assimilation surface area of one plant and the leaf surface index of crops according to the crop growth phases in the soil and climatic conditions of Kursk region. Materials and methods. The studies were conducted in 2022 and 2023 in the field experience at Federal Agricultural Kursk Research Center in grain-fallow crop rotation. The experimental scheme includes the study of three cultivars – Suzdalets, Prometheus, Despina. The second factor is seeding rates: 3, 4, 5, 6 million units of viable seeds per 1 ha. The third factor is the levels of mineral fertilization: control without fertilizers and N₃₀P₃₀K₃₀. Results. It was found that the assimilation surface area of one spring barley plant in the seedling stage depended to a greater extent on the cultivar (by 40 %), and it also increased under the influence of mineral fertilization (by 16 %). The leaf area index of spring barley in the seedling stage depended by 89 % on the seeding rate. During the tillering stage, the leaf area depended by 72 % on the year conditions. Research during the crop blooming stage revealed that the main factor influencing the assimilation surface area and leaf area index was the year of study (31 and 44 %, respectively), the cultivar factor provided 23 and 27 % of the indicator variation, respectively, and the mineral fertilization – 20 and 30 %, respectively. During the milk-ripe stage, due to the leaves dying off, a decrease in the photosynthetic parameters of spring barley is observed. Conclusion. It has been determined that the assimilation surface area of one plant and the leaf area index are very dynamic indicators and largely depend on the year of research, the cultivar and the mineral fertilization. During the initial period of crop growth, the leaf area index is affected by the seed application rate.

Assessment of Method and Application Schedule of Fertilizer N and K on Growth and Productivity of Summer Planted Sugarcane Crop (Saccharum officinarum L.) under Wide Spacing

Present investigation was carried out at Regional Research Station, Uchani (Karnal) of CCS Haryana Agricultural University, Hisar, India during 2020-21 to assess the effect of method and schedule of fertilizer application on growth, yield attributes and cane yield of summer planted sugarcane (Saccharum officinarum L.) crop under wide spacing (120 cm). The experiment was arranged in split plot design with two methods of fertilizer application (B1-broadcasting and B2- band placement) as main plot treatments and four sub plot treatments which include application of recommended dose of N and K fertilizer (RDF) in different number of splits at different no. of days after planting (DAP) i.e. T1 (five splits), T2 (six splits), T3 (seven splits) and T4 (three splits). Results concluded that majority of growth parameters, yield attributes and cane yield were significantly affected by both main and sub plot treatments at different stages of crop growth period. Treatment B2 registered significantly higher tiller population (110.59 and102.68 000 ha-1 at 60 and 120 DAP respectively), plant height (91.16, 141.18, 400.12 and 412.13 cm at 60, 120, 180 and 240 DAP respectively), no. of millable canes (NMC) (100.79 and 96.58 000 ha-1 in mid-September and at harvesting respectively) cane length (234.64 cm at harvesting) and cane yield (93.16 t ha-1)compared to B1. Among sub plot treatments, T1 outperformed all the other treatments in terms of growth, yield attributes and cane yield. Treatment T1 registered maximum plant height (150.43, 411.0 and 427.45 cm at 120, 180 and 240 DAP respectively), tiller population (104.72 000 ha-1 at 120 DAP), NMC (102.06 and 95.20 000 ha-1 in mid-September and at harvesting respectively) and cane yield (94.83 t ha-1). Germination percentage, cane girth, no. of internodes per cane and length of internodes was not significantly affected either by main or sub plot treatments.

Macronutrient Status and Soil Chemical Properties as Influenced by Methods and Schedule of Fertilization in Karnal Alfisols under Sugarcane (Saccharum officinarum L.) Cultivation

An experiment was conducted at the Regional Research Station , Uchani (Karnal) of CCS Haryana Agricultural University, Hisar, India during 2020-21 to assess the effect of the method and schedule of fertilizer application on macronutrient status viz. available Nitrogen (N), Phosphorus (P) and potassium(K) and soil chemical properties i.e. soil pH, electrical conductivity (EC) and soil organic carbon (SOC) at different intervals of the crop growth period. The experiment was laid out in split plot design with two methods of fertilizer application (B1-broadcasting and B2- band placement) as main plot treatments and four sub plot treatments consisting of the application of recommended doses of N and K fertilizer (RDF) in the different number of splits at different number of days after planting (DAP) i.e. T1(five splits), T2(six splits), T3(seven splits) and T4(three splits). Results elucidated that the availability of all the macronutrients was significantly affected by both sub and main-plot treatments at different stages of crop growth period. Available N content was found to be significantly higher in B2 compared to B1 at all the time intervals from 75 DAP (131.86 Kg ha-1 ) to harvest (145.91 Kg ha-1 ) reaching the maximum at 180 DAP (142.80 Kg ha-1). Among the sub plot treatments, T4 and T1 respectively reported significantly higher values of available N from 75 DAP (134.51 Kg ha-1 ) to 90 DAP (147.08 Kg ha-1) and 90 DAP(153.10 Kg ha-1) to 150 DAP(162.11 Kg ha-1). At 180 DAP and at the time of harvesting, significantly higher values of available N (159.21 Kg ha-1 and 157.01Kg ha-1 ) were observed in treatments receiving fertilizer in T2 and T3 splits respectively. Available K content was significantly higher in B1 compared to B2 at all the time intervals except at 0, 150, 180 DAP and at harvest where the difference was not significant. Higher values of available K were reported under T4 upto 75 DAP (225.30 Kg ha-1) and thereafter, T1 exhibited significantly higher available K values upto 150 DAP (222.06 Kg ha-1). At 180 DAP and at the time of harvesting, significantly higher values of available K (225.10 Kg ha-1 227.48 Kg ha-1) were observed in T2 and T3 respectively. Available P content was significantly higher (24.63 Kg ha-1) in B1 compared to B2 at the time of harvesting. Soil pH, EC and SOC did not registered any significant change under any treatment. Overall treatment B2 and T1 emerged out be best among main and sub-plot treatments respectively. Availing the suitable methods and schedule of fertilization improved the status of micronutrients in soil during the active growth stage of crop.

Spatial–temporal characteristics and influencing factors on the crop-growing period in the continental-temperate climate of Hexi Oasis

Spatial–temporal characteristics and influencing factors on the crop-growing period in the continental-temperate climate of Hexi Oasis

Role of Mulching in Dryland Agriculture

The efficient use of water is crucial factor during crop growth periods which can greatly improve the yield .soil moisture is the most limiting factor in dryland agriculture. It is lost as evaporation from the soil surfaces and as transpiration from the plant surfaces .Evaporation has to be arrested as it is not directly related to productivity whereas transpiration can be reduced to some extent without affecting the productivity of plants. The evaporation losses can be reduced by applying mulches. The agriculture in dryland can be done with mulching in different ways as stubble mulching, plastic mulching, straw mulching and vertical mulching Therefore, conservation of soil moisture by using mulching may be an efficient option to save water as well as rising production in dryland farming.

Effects of Biochar Application before and after Freeze-Thaw on Soil Hydrothermal and Cotton Growth under Drip Irrigation

Biochar as an organic soil conditioner has colossal application potential. Many recent studies revealed the influence of biochar on the soil during the crop growth period. However, few studies considered the effect of seasonal freeze-thaw on biochar’s improvement effect. Therefore, we conducted a field experiment to observe the impact of biochar on soil and cotton (Gossypium hirsutum L.). We used four biochar application rates (0.33%, 0.66%, 1.00%, and 1.33% of soil mass fraction) and applied biochar in the cotton field before and after seasonal freeze-thaw, respectively. The results showed that applying biochar after freeze-thaw was more effective on soil water storage and soil temperature preservation during the cotton growth period. Moreover, applying biochar with 0.66% soil mass fraction after freeze-thaw improved the cotton biomass by 5.31~36.13%, leaf area index by −10.82~32.52%, and seed cotton yield by 3.88~21.98%. Based on the principal component analysis of cotton fiber quality, we found that 0.66% biochar application after freeze-thaw improved cotton fiber most significantly. In total, applying biochar at 0.66% soil mass fraction after freeze-thaw was the most optimal application mode for improving soil hydrothermal conditions, cotton growth, and fiber quality. Our study can provide a scientific reference for applying biochar in northern Xinjiang, China.

Productivity and water-use efficiency of rice (Oryza sativa) cultivars under different irrigation regimes and systems of cultivation

A field experiment was conducted on clay loam soils of the Indian Institute of Rice Research, Hyderabad, Telangana, during the rainy (kharif) seasons of 2017 and 2018, to study the performance of rice (Oryza sativa L.) cultivars under different irrigation regimes and systems of cultivation. The treatments consisted of 2 irrigation regimes, viz. alternate wetting and drying (AWD), and saturation as main plot treatments, while 3 systems of cultivation, viz. system of rice intensification (SRI), drum seeding (DS) and normal transplanting (NT) as subplot treatments and assessed 4 cultivars, viz. ‘DRR Dhan 42’, ‘DRR Dhan 43’, ‘MTU 1010’ and ‘NLR 34449’ as sub-subplot treatments. Total 24 treatment combinations were laid out in split-plot design with 3 replications. Application of water through the AWD method saved around 11–14% of the total water requirement during the crop-growth period. Irrigation by AWD resulted in significantly higher irrigation water productivity and water-use efficiency (WUE). The SRI method required the lowest amount of water (11.61% and 13.21% less of mean applied than drum seeding and normal transplanting respectively). Significantly higher water productivity and WUE were registered with SRI. ‘DRR Dhan 43’ recorded higher water productivity as well as WUE as compared to the other cultivars during both the years of study owing to higher productivity.

Application effect of different oxygenation methods with mulched drip irrigation system in Xinjiang

When crop roots are in a low oxygen environment for a long time, it will lead to a series of problems. To improve soil oxygen conditions, a method of oxygenation irrigation is increasing the dissolved oxygen (DO) concentration in irrigation water. However, its application effect in a mulched drip irrigation system is not clear. In this study, a field experiment was conducted in Xinjiang to investigate the actual effect of oxygenation irrigation in field planting. We set up mechanical oxygenation (AO), venturi oxygenation (VO), and four chemical oxygenations with different DO concentrations (CO1–4). The results showed that physical oxygenation (AO, VO) was limited by the saturated DO of irrigation water. Compared with venturi oxygenation, mechanical oxygenation could reach the saturated DO faster and had higher stability of DO concentration during single irrigation. The chemical oxygenation was not limited by the saturated DO. The maximum DO in irrigation water would also increase with the increase in the amount of oxygen enhancer, but it needed more reaction time than the physical oxygen to reach a stable state. The oxygenated water would be affected by water temperature and delivery distance in the mulched drip irrigation system, resulting in the continuous decline of DO during the irrigation process. For those oxygenated water with saturated DO under different oxygenation methods (AO, VO, and CO1), when they entered the soil, there was no significant difference in the changing trend of DO. In an irrigation process, with the increase of DO, the actual oxygenation efficiency in the soil also increased. The DO concentration of irrigation water was increased from 3.9 mg L−1 to 9.1 mg L−1, and 10 times of irrigation was carried out during the crop growth period, then soil oxygen could be increased by an average of 6.72∼6.89%. By increasing the DO of irrigation water, the soil oxygen condition of mulched drip irrigation can be improved. Under the condition of saturated DO, each oxygenation irrigation had no significant impact on the soil physical and chemical properties. After two years of irrigation, the chemical oxygenation using sodium percarbonate had increased the soil EC, pH, and Na+ content, which means slightly intensified the soil salinization.

Modeling heat-water-salt transport, crop growth and water use in arid seasonally frozen regions with an improved coupled SPAC model

The soil–plant-atmosphere continuum (SPAC) that is a dynamic, interactive and coupled system is particularly complicated in arid seasonally frozen regions (ASF regions) with the effects of soil freeze–thaw process and salinity. A quantitative understanding of heat-water-salt transport and crop growth in the SPAC over an entire agricultural year (agr-year) is an importance of promoting best practices for water use and crop production. In this paper, an improved coupled SPAC model (SHAW-SC) is presented and applied for continuously simulating the SPAC system of ASF regions over an agr-year. The model is developed based on modifying the SHAW model (version 3.0) and incorporating the EPIC crop growth module. The main new features of the SHAW-SC include extending the model capability for canopy growth and yield formation, improving the description of soil solute transport in the shallow groundwater systems, and providing functions to describe the effects of surface mulching on soil evaporation and salinity stress on crop growth and transpiration. Model testing and application were conducted with two agr-year data at the sunflower experimental field in irrigated areas of the upper Yellow River basin, northwest China (with an arid and cold climate). Simulations of soil water content, temperature, and crop growth indicators fitted well with the observations both in calibration and validation (with NSE > 0.64 and sufficiently small RMSE); meanwhile, simulation of salinity concentration was also satisfactory (NSE: 0.32 and 0.83; RMSE: 1.09 and 2.44 g L−1), despite the complexity of salt transport and the measurement difficulty. In addition, the comparison with previous experimental results also showed the reasonability of modeling results. Then, a comprehensive and quantitative analysis of the SPAC dynamics was conducted over an agr-year, with identifying five characteristic periods (i.e. pre-freezing, soil-freezing, soil-thawing, pre-planting and crop growth periods). Results provided a fuller understanding of the characteristics of water-salt dynamics and balance components, and the related issues of crop stress, water use and salinity control on an entire agr-year scale. Model testing and application proved that the proposed SHAW-SC was an efficient tool to simulate coupled processes of heat-water-salt transport and crop growth for ASF regions, and as well an enhancement of current SPAC models for practical field applications.