Effect Of Fertilizer Management Research Articles

Global patterns of soil phosphatase responses to nitrogen and phosphorus fertilization

Hydrolysis of organic phosphorus (P) by soil phosphatases is an important process of P cycling in terrestrial ecosystems, significantly affected by nitrogen (N) and/or P fertilization. However, how soil acid phosphatase (ACP) and alkaline phosphatase (ALP) activities respond to N and/or P fertilization and how these responses vary with climatic regions, ecosystem types, and fertilization management remain unclear. This knowledge gap hinders our ability to assess P cycling and availability from a global perspective. We performed a meta-analysis to evaluate the global patterns of soil ACP and ALP activities in response to N and/or P addition. We also examined how climatic regions (arctic to tropical), ecosystem types (cropland, grassland, and forest), and fertilization management (experiment duration and fertilizer type and application rate) affected changes in soil phosphatases after fertilization. It was shown that N fertilizer resulted in 10.1% ± 2.9% increase in soil ACP activity but a minimal effect on soil ALP activity. In contrast, P fertilizer resulted in 7.7% ± 2.6% decrease in soil ACP activity but a small increase in soil ALP activity. The responses of soil ACP and ALP activities to N and/or P fertilization were largely consistent across climatic regions but varied with ecosystem types and fertilization management, and the effects of ecosystem types and fertilization management were enzyme-dependent. Random forest analysis identified climate (mean annual precipitation and temperature) and change in soil pH as the key factors explaining variations in soil ACP and ALP activities. Therefore, N input and ecosystem types should be explicitly disentangled when assessing terrestrial P cycling.

Effect of soil tillage and nitrogen fertilizer management on methane emissions from irrigated rice fields in Central Java, Indonesia

Effect of soil tillage and nitrogen fertilizer management on methane emissions from irrigated rice fields in Central Java, Indonesia

Modelling maize yield impacts of improved water and fertilizer management in southern Africa using cropping system model coupled to an agro-hydrological model at field and catchment scale

AbstractThis study quantifies the effect of fertilizer and irrigation management on water use efficiency (WUE), crop growth and crop yield in sub-humid to semi-arid conditions of Limpopo Province, South Africa. An approach of coupling a cropping system model (DSSAT) with an agro-hydrological model (SWAT) was developed and applied to simulate crop yield at the field and catchment scale. Simulation results indicated that the application of fertilizer has a greater positive effect on maize yield than irrigation. WUE ranged from 0.10–0.57 kg/m3 (rainfed) to 0.84–1.39 kg/m3 (irrigated) and was positively correlated with fertilizer application rate. The combined application of the variants with deficit irrigation and fertilizer rate (120:60 kg N:P/ha) for maize turned out to be the best option, giving the highest WUE and increasing average yield by up to 5.7 t/ha compared to no fertilization and rainfed cultivation (1.3 t/ha). The simulated results at the catchment scale showed the considerable spatial variability of maize yield across agricultural fields with different soils, slopes and climate conditions. The average annual simulated maize yield across the catchment corresponding to the highest WUE ranged from 4.0 to 7.0 t/ha. The yield gaps ranged from 3.0 to 6.0 t/ha under deficit irrigation combined with 120N:60P kg/ha and ranged from 0.2 to 1.5 t/ha when only applying deficit irrigation but no fertilizer. This information can support regional decision makers to find appropriate interventions that aim at improving crop yield and WUE for catchments/regions.

Effects of irrigation and nitrogen fertilizer management on wheat grain baking quality based on the SiriusQuality2 crop model

AbstractThe baking quality of wheat grain is significantly affected by irrigation and nitrogen fertilizer management. This study aimed to model the impacts of nitrogen and water stress on winter wheat grain protein composition using SiriusQuality2. SiriusQuality2 was calibrated by using sufficient nitrogen and water treatments and used to evaluate 16 treatments in semi‐arid regions. Then, simulated baking quality and yield over a past 51‐year period were used to screen and optimize the selected 203 management practices. The evaluated simulation results suggest that all relative root mean square errors were less than 0.3, and the simulation results were excellent or good. Irrigation and nitrogen fertilization were beneficial to yield and grain protein content (GPC), while grain baking quality had adverse responses to irrigation. The GPC no longer increased, and the baking quality decreased with excess nitrogen fertilization (262.5 kg ha−1). Increasing the irrigation frequency and days after sowing were always conducive to baking quality. The optimal management, with a basal dressing of 315‐kg ha−1 nitrogen fertilization and 180‐mm irrigation depth at the wintering stage and jointing stage, was selected. Optimized management practices could simultaneously meet the multiple requirements of high grain quality and yield.

Durum Wheat Production as Affected by Soil Tillage and Fertilization Management in a Mediterranean Environment

Several strategies have been proposed recently to reduce the accumulated harmful circumstances of intensive conventional farming practices. The adoption of conservation soil tillage and organic fertilization techniques could contribute to achieving this goal. The study was conducted over a three-year trial to assess the effects of soil tillage practices (plough; subsoil; spading) and fertilization management (inorganic vs. organic) on durum wheat growth dynamics and productivity in a Mediterranean environment. The chlorophyll concentration (CC) was evaluated using an MC-100 chlorophyll meter, and Green Area (GA) was extracted from red-green-blue (RGB) digital images acquired with a commercially available digital camera. These non-destructive low-cost methods were used to examine crop status and its reactions to climate conditions over three consecutive growing seasons in the field. A positive strong linear relationship between both CC and GA against grain yield in each growing season was identified. The study highlights that CC and GA methods are valuable tools to assess crop development under Mediterranean conditions. The results indicated that the applied conservation tillage systems, such as subsoil tillage and using the spading machine, along with organic fertilization with compost, are valuable choices in the Mediterranean basin for sustainable and higher crop production (13%) compared to the conventional traditional system.

Heavy Metal Evaluation of Overused Commercial Fertilizers and Their Interactions with Soil Properties

Şanlıurfa province has 36% of the agricultural areas in Turkey and 64.1% of the agricultural areas in the GAP Region. With approximately 600 000 tons of chemical fertilizer consumption in 2021, it is the province with the most fertilizer consumption in Turkey. This causes some negative and high environmental risks such as salinization in the soil, heavy metal (HM) accumulation, deterioration of nutrient balance, damage to microorganism activity, and formation of eutrophication in the region. The objective of this study was to determine the HMs (Zn, Ni, Mn, Cu, Mo, Pb, Cd) concentrations of the soils and some commercial fertilizers overused, and evaluate their interactions with soil properties. The average values of HM concentration of the soil are as follows; 32.65 and 46.88 mg kg-1 Zn; 649.03 and 730.58 mg kg-1 Mn; 79.86 and 95.54 mg kg-1 Ni; 0.15 to 0.27 mg kg-1 Cd; 0.26 and 0.97 mg kg-1 Mo; 8.54 and 18.67 mg kg-1 Pb; 19.45-25.37 mg kg-1 Cu. HM contents of some fertilizers were found to be very high in this study. This causes an increase in the HM concentration in the soil. HMs concentrations of several soil samples exceeded the threshold level of Europe standards except for Ni, Mo, and Mn. Study results can help the authorities to develop effective fertilizer management strategies for the Harran Plain, which has once again revealed the necessity of applying agricultural activities such as fertilization with a fertilization program prepared under expert control according to the results of soil analysis.

Effect of deficit irrigation and soil fertility management on wheat production and water productivity in the Upper Blue Nile Basin, Ethiopia

In the Ethiopian Upper Blue Nile Basin, like in other regions in the world, agricultural productivity is declining due to water scarcity owing to longer dry seasons coupled with soil acidity−induced fertility problems. Wheat is one of the major food security crops in Ethiopia but its productivity is reduced due to water scarcity, especially during the irrigation season. Addressing these problems might be essential to increase productivity. This study explores the effect of deficit irrigation (DI) combined with lime, manure and inorganic fertilizer on wheat production and water productivity (WP) in the Koga irrigation scheme, Ethiopia. Four levels of DI strategies (100% ETc or 0% deficit as a control, 80%, 60% and 50% ETc) were applied for two irrigated seasons. Five levels of soil fertility management were applied for four consecutive cropping seasons: (i) 0.86 t ha−1 lime combined with 3 t ha−1 manure and full dose urea and NPS−B (hereafter referred to as inorganic fertilizer) (L3); (ii) 1.15 t ha−1 lime combined with 3 t ha−1 manure and full-dose inorganic fertilizer (L2); (iii) 1.43 t ha−1 lime combined with 3 t ha−1 manure and full dose inorganic fertilizer (L1); (iv) 3 t ha−1 manure combined with full dose inorganic fertilizer (M); and (v) full dose inorganic fertilizer alone (C). The grain yield and biomass data were collected at harvest from a sample area of 2 m × 3 m from each plot with three replicates. The effect of DI and liming, as well as manuring on average grain yield and biomass, were highly significant. Under all irrigation scenarios, higher grain yield and biomass were found at L1, L2, L3 and M (in that order), compared with C. The highest WP was obtained at 50% ETc irrigation dose, compared with 60%, 80% and 100% ETc (in that order). Yet, the lowest WP was found at C under all irrigation scenarios compared with L1, L2, L3 and M. The WP increased when the amount of water supply decreased and liming doses increased. The application of full dose lime and manure combined with 50% ETc DI resulted in comparable grain yield, biomass and WP as 100% ETc full irrigation at L3 and M. It could be concluded that liming and manuring could be used to mitigate the yield penalty effect of DI in the study area. In scenarios where farmers have to pay for water, profitability rises as the irrigation water supply reduces. Thus, under such conditions, a 50% ETc irrigation scenario is more profitable than scenarios with 60%, 80% and 100% ETc irrigation.

Optimizing urea deep placement to rainfall can maximize crop water-nitrogen productivity and decrease nitrate leaching in winter wheat

The deep placement of urea fertilizer is considered an effective strategy for crop growth and yield formation. How crop root morphology and resource utilization respond to altered rainfall amount and deep urea fertilizer placement is still not fully understood. Thus, we conducted a two-year field experiment in the semi-humid region to assess the effects of different urea fertilizer placement depths of 5 cm (D5, conventional surface fertilization), 15 cm (D15), 25 cm (D25), and 35 cm (D35) under three rainfall conditions (dry year = 125 mm, P125; normal year = 200 mm, P200; wet year = 275 mm, P275) on root distribution, resource utilization and yield of wheat. Deep urea placement significantly increased root length density and root weight density in the 20–60 cm soil layer, which caused a significant increase in wheat nitrogen (N) uptake. Compared with D5, deep urea placement significantly increased the crop N uptake (10.4–27.6 %), grain N content (1.2–18.7 %), N recovery efficiency (NRE, 0.9–16.7 %) and N partial productivity (PFPN, 1.1–20.0 %) in dry and normal years, and D15 promoted those by 0.9 %, 1.3 %, 3.7 % and 1.1 % over D5 under wet year. Additionally, compared with D5, deep urea placement increased crop water productivity (WP) and yield by 9.6–23.9 % and 3.2–20.0 % under dry and normal years, and D15 increased those by 1.1 % and 0.5 % in wet year. The accumulated nitrate contents in the 0–100 cm soil layer was 4.7–14.5 % higher under deep urea placement than D5. Placement of urea at depths of 28.0–30.0 cm, 20.7–21.6 cm and 12.3–13.1 cm in the dry, normal and wet years maximized the wheat yield, grain N content and WP. Moderate deep urea placement according to variable precipitation conditions can be an effective fertilizer management strategy for sustainable wheat development.

Effect of Different Fertility Management Practices on Plant Population and Mortality in Chickpea (Cicer arietinum L.)

Aims: To assess the effect of Humic acid (HA), Plant growth-promoting bacteria (PGPR), and Recommended dose of fertilizer (RDF) alone or in combination on plant population and mortality percentage in Chickpea (Cicer arietinum L.).
 Study of Design: The experiment was laid out in Randomized block design (RBD) with three replications.
 Place and Duration: A field experiment was conducted during the rabi season in the year 2020-21 and 2021-2022 at D6 Block, Norman E. Borlaug Crop Research Center at G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand (India).
 Treatments Details: Total ten treatments were used. The details of the treatments are as follows:T1- Absolute control, T2 - Humic acid @ 2.5 kg/ha (soil application), T3 -Humic acid @ 20 g/kg of seed (seed treatment), T4 - PGPR @ 20 g/kg of seed (seed treatment), T5- RDF through 150 kg NPK mixture (12:32:16 Grade), T6 -RDF + HA (soil application), T7 -RDF +HA (seed treatment), T8- RDF +PGPR (Seed treatment), T9- HA (soil application) +PGPR (seed treatment), T10- RDF + HA (soil application)+PGPR (seed treatment).
 Methodology: For plant population, the number of plants that emerged in the second row from both sides of the field were counted at 30 DAS and at harvest stage then averaged and calculate the number of plants for 1 m2 area. The mortality percentage was calculated by using the following formula: 
 
 Results: Findings of the investigation revealed that the effect of different fertility management on plant population was found not significant, but it was found significant in mortality percentage. Among the sole application of treatments T2 (Humic acid @ 2.5 kg/ha (soil application) and T4 (PGPR @ 20 g/kg of seed (seed treatment) recorded minimum mortality percentage, while among the combination treatments, T10 (RDF+HA (soil application) + PGPR as seed treatment) recorded minimum percentage of mortality.

SPATIAL AND TEMPORAL FEATURES OF DEHUMIFICATION OF CHERNOZEMS OF THE PRYDNISTERSKA UPLAND

Purpose. In the structure of the soil cover of the Prydnisterska upland, the area of chernozems is 4 060 km2. The overall rate of plowing up of the territory reaches 80%. The agricultural use of chernozems led to the transformation of almost all processes and properties, but these changes were most reflected in the humus state. A decrease in the intake of organic matter and an increase in its mineralization led to an active manifestation of dehumification. Therefore, the study of this problem will provide a scientific basis for effective fertility management, analyze the current state and propose measures to restore the ecological stability of chernozems at the regional level. The purpose of the research is to characterize the dynamics of the humus content in the chernozems of the Prydnisterska upland during the industrial period (from the beginning of the 20th century to the present), as well as to analyze the extent of the manifestation of dehumification of chernozems in flat and slope areas. To achieve this goal, the following were carried out: the field stage of work on the selection of soil samples, laboratory analytical studies of the humus content, analysis of data from archival materials and the results of preliminary studies on the relevant topic. The object of the research comprises typical chernozems and podzolized chernozems of the Prydnisterska upland. The subject of the study is the humus content of the arable horizon (0–20 cm) of chernozems of flat and slope relief with varying degrees of erosion. Data & Methods. The study of the problem of dehumification of chernozems of the Prydnisterska upland was carried out using generally accepted methods: comparative-geographical, comparative-analytical and comparative-profile. Archival materials of soil science expeditions, statistical data of preliminary agrochemical surveys and our own research results obtained during 2019–2020 (research sites “Savyntsi», «Ruda», «Basivka» and «Kadyivtsi») were used for a comparative analysis of the dynamics of the humus content in chernozems over the last century. Results. Analysis of the data on the humus content in the chernozems of the Prydnisterska upland during the industrial period, at different times, confirmed the active manifestation of dehumification. The intensification of agriculture in the region, neglect of soil protection technologies and insufficient application of organic fertilizers have led to the formation of a negative humus balance. For 106 years (from 1914 to 2020), the humus content of the chernozems of the Prydnisterska upland has decreased by 30–45%. The most intense losses of the organic component have been recorded by the beginning of the 90s of the 20th century. The total loss of humus by chernozems during this period amounted to 36–48 t/ha. According to the accepted estimates of the humus content, the chernozems of the study area in modern soil management conditions are characterized as low-humus with a humus content (3–4%). Statistical data indicate that the intensity of dehumification has decreased over the past 6 years, but the negative humus balance remains. Losses of humus (in the 0–20 cm layer) decreased to the level of 0.28–0.36 t/year, however, these data are correlated depending on the structure of crop rotations, soil cultivation technologies and fertilization rates. According to the results of the study, it has been found that the variability of the humus content within the arable horizon (0–20 cm) increases with a change in the morphometric parameters of the relief and the intensity of manifestation of erosional degradation. In particular, a critical situation is observed on slopes with a steepness of 5–6 °, which are distinguished by the lowest reserves of humus. Dehumification of chernozems of the Prydnisterska upland is the result of an unbalanced anthropogenic impact. Optimization of this problem requires the widespread introduction of soil protection technologies on slope areas of the relief, the introduction of an appropriate amount of organic fertilizers, sowing green manure crops, conservation of eroded areas.

Effect of Irrigation and Fertilizer Management on Rice Yield and Nitrogen Loss: A Meta-Analysis.

Irrigation and nitrogen fertilizer application are two important factors affecting yield and nitrogen loss in rice fields; however, the interaction effects of different irrigation schedules and combined management of nitrogen fertilizer application on yield and nitrogen loss in rice fields remain unknown. Therefore, we collected 327 sets of data on rice yield and 437 sets of data on nitrogen loss in rice fields from 2000 to 2021 and investigated the effects of different water-saving irrigation schedules, nitrogen application levels, and water–nitrogen couplings on rice yield, nitrogen use efficiency, and nitrogen loss (N2O emissions, nitrogen runoff, nitrogen leaching, and ammonia volatilization) by meta-analysis using conventional flooding irrigation and no nitrogen treatment as controls. The results showed that alternate wet and dry irrigation and controlled irrigation had increasing effects on rice yield. Alternate wet and dry irrigation had a significant yield-increasing effect (average 2.57% increase) and dry cultivation significantly reduced rice yield with an average 21.25% yield reduction. Water-saving irrigation reduces nitrogen runoff and leaching losses from rice fields but increases N2O emissions, and alternate wet and dry irrigation has a significant effect on increasing N2O emissions, with an average increase of 67.77%. Most water-saving irrigation can increase nitrogen use efficiency. Among water-saving irrigation methods, the effect of controlled irrigation on increasing nitrogen use efficiency is 1.06%. Rice yield and nitrogen use efficiency both showed a trend of increasing then decreasing with nitrogen fertilizer application, and nitrogen loss gradually increased with the amount of nitrogen fertilizer input. Water–nitrogen coupling management can significantly reduce nitrogen loss in rice fields while saving water and increasing yield. Based on the analysis of the data in this study, when the irrigation amount was 300~350 mm and the nitrogen application amount was 200~250 kg/ha, the rice yield and nitrogen fertilizer use efficiency were at a high level, which corresponded to the irrigation schedule of controlled irrigation or alternating wet and dry irrigation in the literature. However, different rice-growing areas are affected by rainfall and land capability, etc. Further optimization and correction of the adapted water and fertilizer management system for paddy fields are needed. The optimal water–nitrogen pattern of this study can achieve high rice yield and reduce nitrogen loss.

Effects of long-term organic matter application on soil carbon accumulation and nitrogen use efficiency in a double-cropping rice field

Increasing soil carbon (C) sequestration in paddy field and improving rice nitrogen use efficiency (NUE) are vital for sustainable agriculture and environmental protection. It was a benefit practice for achieving these goals by taken rice straw and organic manure managements. However, there is still need to further investigate the effects of different long-term fertilizer managements on soil C sequestration and NUE under the double-cropping rice system in southern of China. Therefore, the effects of different long-term (36-years) fertilizer practices on soil C sequestration and NUE under the double-cropping rice system in southern of China were investigated in the present paper. The field experiment was included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM), and without fertilizer input as a control (CK). This result indicated that soil C content at plough layer in paddy field with RF and OM treatments were increased, compared with MF and CK treatments. Besides input C directly into paddy field, soil original organic C accumulation with RF and OM treatments were increased by 1.54% and 3.01%, compared with MF treatment. This result indicated that soil TOC content increase rate and annual topsoil organic C sequestration rate in paddy field with RF and OM treatments increased by 55.56%, 88.89% and 48.05%, 76.62%, compared with MF treatment, respectively. Compared with MF treatment, NUE with RF and OM treatments increased by 10.43% and 22.61%, respectively, mainly due to increasing soil organic C. Grain yield of double-cropping rice with RF and OM treatments increased by 1009.5 and 1166.5 kg ha−1, compared with MF treatment, respectively. This result indicated that there was significantly correlation between NUE/NUENPK and TOC content with RF and OM treatments, at early rice and late rice growth seasons. Therefore, it was benefit practice for increasing soil carbon sequestration and improving rice NUE in the double-cropping rice system with long-term application of rice straw and organic manure managements.

Responses of soil respiration and microbial community structure to fertilizer and irrigation regimes over 2 years in temperate vineyards in North China

Fertilizer and irrigation regimes can profoundly affect soil carbon (C) emissions, which influence soil organic carbon (SOC) storage. However, information regarding the effects of fertilizer and irrigation management on the components of soil respiration (Rs) and the underlying microbial community characteristics in vineyard ecosystems remains limited. Therefore, a 2-year field experiment was conducted in a wine-grape vineyard (WGV) and a table-grape vineyard (TGV). Each vineyard included two fertilizer and irrigation regimes: farmers' practice (FP) and recommended practice (RP). The trenching method was employed to separate Rs into heterotrophic respiration (Rh) and autotrophic respiration (Ra). Additionally, the SOC storage and soil microbial community structure at 0–20 cm soil depth were determined after the 2-year experiment. The results showed that the fertilizer and irrigation regimes caused no effect on Ra. Compared with the FP treatment in WGV and TGV, the RP treatment significantly (P < 0.05) decreased the average daily Rh by 15.13 % and 17.11 %, which contributed to the annual Rs values at the whole-vineyard scale decreased by 8.93 % and 11.78 %, respectively. Besides, compared with the initial value, the SOC storage under RP treatment were effectively increased by 6.39 % and 6.33 % in WGV and TGV, respectively. Low annual total Rh was partially ascribed to the significant (P < 0.05) decline in Proteobacteria and Bacteroidetes relative abundance, thus reducing the decomposition rate of SOC. Compared with WGV, the fertilizer and water input was higher in the TGV, which resulted in the annual total Rs and Rh values at the whole-vineyard scale was increased by 11.53 % and 15.74 %, respectively, while the annual total Ra was decreased by 18.83 % due to the lower grapevine density and more frequent summer pruning. Overall, RP treatment was found to be a suitable strategy for reducing soil C emissions and benefiting SOC storage in vineyards around North China.

Effects of nitrogen fertilizer management on maize yield and nitrogen use efficiency: Based on farmer Survey in Quzhou county, North China Plain

The farmer survey was conducted in Quzhou county, Hebei province of China in three villages (Wang Zhuang, Xing yuan, and Sitton) with the objectives of elucidating the effects of nitrogen fertilizer (N) on maize production and nitrogen use efficiency (NUE). A total of 61 maize producers were randomly selected and interviewed. The educational level result revealed that about 8% of sampled farmers have no formal education, 11.6% have a basic level education, 21.6% have completed the middle-level education, and 58.3% have upper-level education. Most producers use nitrogen (40%), then phosphorus fertilizer (25%), and thirdly the compound fertilizer NPK, the least used fertilizers in the region are potassium and organic fertilizers such as straw and vegetable remains. The farmer applies twice, at base planting and in vegetative tasselling (VT), also, fertilizer N is the most used by farmers, whose application rates were higher ranging from 375 kg ha -1 representing 49.2%, followed by 300 kg ha -1 representing 39.3%, and finally, a small number of producers apply 225 kg ha -1 of fertilizer which represents 11.5%. The yield of maize was around 6443.3 kg ha -1 in the region, it was observed that the partial factor productivity of nitrogen remains low as compared with the optimal N management, the value was 20.4 kg kg -1 , and the rates of cost fertilizer was 125￥ 50 kg -1 . We can conclude that the low cost of N and less knowledge of fertilizer management is the motivation for excessive utilization. However, regular training of producers can help adopt good practices of optimal N management, minimize environmental risks, and can save money, and reduce the cost of production. Key Words: Fertilizer, maize production, nitrogen management, partial factor productivity DOI: 10.7176/JBAH/12-12-05 Publication date: June 30 th 2022

Intelligent Crop Recommendation System using Machine Learning

Agriculture plays a critical role in the entire life of a given economy. Choosing the wrong crop for the farmer based on the soil needs results in significant losses. Therefore, the problem with this approach is addressed to agricultural accuracy. Precision agriculture is the science that helps increase yields and make management decisions using advanced technology and new tools. It is a new concept adopted globally to increase productivity, reduce labor time, and provide effective fertilizer management and irrigation systems. This can help the farmer by choosing the right crop according to the needs of the soil.

Effects of Nitrogen Fertilizer Management on CH4 and N2O Emissions in Paddy Field

Methane (CH4) and nitrous oxide (N2O) are two extremely important greenhouse gases in the atmosphere. Nitrogen fertilizer is an important factor affecting CH4 and N2O emissions in rice fields. Rational application of nitrogen fertilizer can not only promote high yields of rice but also reduce greenhouse gas emissions. Existing studies have shown that nitrogen reduction and optimal application can effectively improve the nitrogen use efficiency of rice on the basis of ensuring the yield and reduce the loss of N2O caused by nitrification and denitrification of excessive nitrogen in soil. Fertilization times and fertilizer types have significant effects on CH4 and N2O emissions in paddy fields. In this study, a field experiment was conducted for two consecutive years (2019-2020) to study the effects of fertilizer application on CH4 and N2O emissions from rice fields by setting up four treatments consisting of no fertilizer (CK), customary fertilizer application by farmers (CF), twice fertilizer (TT), and 20% replacement of chemical fertilizer by organic fertilizer (OF) using static chamber-gas chromatography. Additionally, the effect of integrating rice yield and integrated global warming potential (GWP) on the greenhouse gas emission intensity (GHGI) per unit of rice yield was analyzed to explore fertilizer application for yield increase and emission reduction in a typical rice growing area in the middle and lower reaches of Yangtze River. The results showed that:① compared with those of CK, the fertilizer treatments reduced CH4 emissions by 14.6%-25.1% and increased N2O emissions by 610%-1836% in both years; ② compared with those of CF, both the TT and OF treatments showed a trend of increasing CH4 emissions and reducing N2O emissions. CH4 emissions increased by 1.8% (P>0.05) and 14.0% (P<0.05), respectively. The annual average of N2O emissions decreased by 63.3% (P<0.05) and 49.2% (P<0.05) in both the TT and OF treatments, respectively. ③ Compared with that of CK, both fertilizer applications increased rice yield and reduced GHGI; compared with that of CF, the OF and TT treatments increased the average annual rice yield by 17.0% and 10.7%, respectively, and reduced GHGI by 6.8% and 13.7%, respectively. The OF treatment had a better yield increase than that of the TT treatment, and the TT treatment had a slightly better emission reduction than that of the OF treatment. In terms of combined yield and GHG emission reduction, both twice fertilizer (TT) and 20% replacement of chemical fertilizer by organic fertilizer (OF) could reduce the intensity of GHG emission per unit of rice yield and achieve yield increase and emission reduction while ensuring rice yield.

Effect of fertilizer management on potassium dynamics and yield of rainfed lowland rice in Indonesia

Effect of fertilizer management on potassium dynamics and yield of rainfed lowland rice in Indonesia

Increased Yield and High Resilience of Microbiota Representatives With Organic Soil Amendments in Smallholder Farms of Uganda.

Organic matter inputs positively affect soil fertility and quality but management effects on the soil and plant microbiome are less understood. Therefore, we studied the response of microbial colonization of the East African highland banana cultivar “Mpologoma” (AAA genome) under different mulch and manure treatments on three representative smallholder farms in Uganda. In general, the gammaproteobacterial community appeared stable with no significant response to organic matter inputs after 24 months of treatment. Significant differences (p < 0.05) in the plant-associated carpo-, phyllo-, and rhizosphere microbial community composition and diversity were found among individual sampled farms, independent of added soil inputs. Across farms, banana fruit harbored a richer and more balanced gammaproteobacterial community than the rhizo- and endospheres. Gammaproteobacterial beta diversity was shaped by the microenvironment (44%) as well as the sampling site (4%). Global effects of treatments in the rhizosphere analyzed using linear discriminant analysis effect size showed significantly enriched genera, such as Enterobacter, under manure and mulch treatments. As shown in previous works, bunch size and total yield were highly increased with manure and mulch, however, our results highlight general short-term microbial stability of Ugandan banana cropping systems with increases in the gammaproteobacterial community.

Climate Overrides Effects of Fertilizer and Straw Management as Controls of Nitrous Oxide Emissions After Oilseed Rape Harvest

Oilseed rape (Brassica napus L.) is an important bioenergy crop that contributes to the diversification of renewable energy supply and mitigation of fossil fuel CO2 emissions. Typical oilseed rape crop management includes the use of nitrogen (N) fertilizer and the incorporation of oilseed rape straw into soil after harvest. However, both management options risk increasing soil emissions of nitrous oxide (N2O). The aim of this 2-years field experiment was to identify the regulating factors of N cycling with emphasis on N2O emissions during the post-harvest period. As well as the N2O emission rates, soil ammonia (NH4+) and nitrate (NO3−) contents, crop residue and seed yield were also measured. Treatments included variation of fertilizer (non-fertilized, 90 and 180 kg N ha−1) and residue management (straw remaining, straw removal). Measured N2O emission data showed large intra- and inter-annual variations ranging from 0.5 (No-fert + str) to 1.0 kg N2O-N ha−1 (Fert-180 + str) in 2013 and from 4.1 (Fert-90 + str) to 7.3 kg N2O-N ha−1 (No-fert + str) in 2014. Cumulative N2O emissions showed that straw incorporation led to no difference or slightly reduced N2O emissions compared with treatments with straw removal, while N fertilization has no effect on post-harvest N2O emissions. A process-based model, CoupModel, was used to explain the large annual variation of N2O after calibration with measured environmental data. Both modeled and measured data suggest that soil water-filled pore space and temperature were the key factors controlling post-harvest N2O emissions, even though the model seemed to show a higher N2O response to the N fertilizer levels than our measured data. We conclude that straw incorporation in oilseed rape cropping is environmentally beneficial for mitigating N2O losses. The revealed importance of climate in regulating the emissions implies the value of multi-year measurements. Future studies should focus on new management practices to mitigate detrimental effects caused by global warming, for example by using cover crops.

Effect of variety and nitrogen fertilizer managements on the growth and yield of Transplant aman rice managements

Varietal selection and appropriate placement of nitrogen fertilizer could reduce the magnitude of nitrogen losses to a considerable extent and improve its use efficiency for better grain production. An experiment was carried out during the period from July to December at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh to evaluate the effect of variety and nitrogen fertilizer management on the growth and yield of transplant aman rice. The treatments consisted of three varieties viz. BR11, BRRI dhan49 and Binadhan-7, and five nitrogen fertilizer managements viz. two depth of placement of USG (Urea Super Granule) and three split applications of prilled urea. The experiment was laid out in a randomized complete block design with three replications. The results showed that the effect of variety and nitrogen fertilizer management significantly influenced all the yield contributing characters except weight of 1000- grains, non-effective tillers hill-1 and panicle length. The highest grain yield (3.69 t ha-1) was obtained from Binadhan-7. In the case of nitrogen fertilizer management, the highest grain yield (4.32 t ha-1) was found from the 6 cm depth placement of USG. The highest grain yield (4.82 t ha- 1) was observed from the interaction of Binadhan-7 with the 6 cm depth of placement of USG. It may be concluded that Binadhan-7 with 6 cm depth of placement of USG appeared as the promising practice to maximize the yield of transplant aman rice.&#x0D; Res. Agric., Livest. Fish.8(3): 281-289, December 2021