The influence of potassium and defoliation of ryegrass on the formation of acidic subsurface layers in stock urine patches

Soil Research ◽  
2005 ◽  
Vol 43 (2) ◽  
pp. 213 ◽  
Author(s):  
J. R. Condon ◽  
A. S. Black ◽  
M. K. Conyers
Keyword(s):  
N Uptake ◽  
Application Rate ◽  
Soil Columns ◽  
Surface Layers ◽  
Downward Movement ◽  
Application Rates ◽  
Subsurface Layers ◽  
N Rates ◽  
Main Effects ◽  
The Impact

This study examined the influence of simulated urine solutions containing various KCl and urea-N rates on the formation of acidic subsurface layers in soil columns. A factorial design was implemented with application rates equivalent to 0, 21, 42, 63, and 84 g urea-N/m2 and 0, 12.5, 25, and 37.5 g KCl-K/m2. The addition of N caused the formation of acidic subsurface layers at depths between 0.02 and 0.10 m. The magnitude of the resultant net acidification and the depth of the most acidic layer increased with N rate. More acidification occurred at depth at the higher N rates due to the downward movement of NH4+-N. The inclusion of K in the simulated urine produced less acidity in the surface layers and more acidity at depth as the K application rate increased owing to competition between K+ and NH4+-N for exchange sites, allowing more NH4+-N to move to depth. The residual acidity in the soil at the completion of the experiment was found to be greater than the alkalinity of plant material. Therefore, acidic subsurface layers are likely to persist after plant death and decomposition. We also examined the impact of defoliation on the resultant pH profiles formed following simulated urine addition. Defoliation accentuated the magnitude of acidic subsurface layers, possibly due to changes in the rate of N uptake. The influence of defoliation was minor compared with the main effects of N addition.

scholarly journals The effect of cutting frequency and nitrogen fertilizer rates on dry matter production, nitrogen uptake and herbage nitrate content.

1980 ◽  
Vol 28 (4) ◽  
pp. 243-251
Author(s):  
L. Sibma ◽  
T. Alberda
Keyword(s):  
N Uptake ◽  
Application Rate ◽  
Nitrate Content ◽  
N Application ◽  
Application Rates ◽  
Matter Production ◽  
N Application Rate ◽  
Cutting Frequency ◽  
N Rates ◽  
Fertilizer Rates

In 3 trials with perennial ryegrass given N in the range 0-1000 kg/ha and from 3 to 28 times/yr, DM production, N uptake and NO3 content in relation to N application rates and cutting frequencies of herbage were compared. Higher N application rates increased the herbage yield more at longer growing periods than at higher cutting frequencies. N uptake was positively affected by the application rate and not or only slightly by the cutting frequency. Consistent with this, appreciably high N conc. (max. 5.4%) were found on av. in the herbage at high fertilizer N rates and frequent cutting than at lower rates and less frequent cutting (1.6%). NO3 content increased during the growing season, especially as the N application rate was higher and the growing periods longer. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Quantifying N2O emissions from intensive grassland production: the role of synthetic fertilizer type, application rate, timing and nitrification inhibitors

2016 ◽  
Vol 154 (5) ◽  
pp. 812-827 ◽  
Author(s):  
M. J. BELL ◽  
J. M. CLOY ◽  
C. F. E. TOPP ◽  
B. C. BALL ◽  
A. BAGNALL ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Fertilizer Application ◽  
Application Rate ◽  
Nitrous Oxide Emissions ◽  
Mineral Fertilizers ◽  
Urea Fertilizer ◽  
Mitigation Options ◽  
Application Rates ◽  
The Impact ◽  
Ipcc Default

SUMMARYIncreasing recognition of the extent to which nitrous oxide (N2O) contributes to climate change has resulted in greater demand to improve quantification of N2O emissions, identify emission sources and suggest mitigation options. Agriculture is by far the largest source and grasslands, occupying c. 0·22 of European agricultural land, are a major land-use within this sector. The application of mineral fertilizers to optimize pasture yields is a major source of N2O and with increasing pressure to increase agricultural productivity, options to quantify and reduce emissions whilst maintaining sufficient grassland for a given intensity of production are required. Identification of the source and extent of emissions will help to improve reporting in national inventories, with the most common approach using the IPCC emission factor (EF) default, where 0·01 of added nitrogen fertilizer is assumed to be emitted directly as N2O. The current experiment aimed to establish the suitability of applying this EF to fertilized Scottish grasslands and to identify variation in the EF depending on the application rate of ammonium nitrate (AN). Mitigation options to reduce N2O emissions were also investigated, including the use of urea fertilizer in place of AN, addition of a nitrification inhibitor dicyandiamide (DCD) and application of AN in smaller, more frequent doses. Nitrous oxide emissions were measured from a cut grassland in south-west Scotland from March 2011 to March 2012. Grass yield was also measured to establish the impact of mitigation options on grass production, along with soil and environmental variables to improve understanding of the controls on N2O emissions. A monotonic increase in annual cumulative N2O emissions was observed with increasing AN application rate. Emission factors ranging from 1·06–1·34% were measured for AN application rates between 80 and 320 kg N/ha, with a mean of 1·19%. A lack of any significant difference between these EFs indicates that use of a uniform EF is suitable over these application rates. The mean EF of 1·19% exceeds the IPCC default 1%, suggesting that use of the default value may underestimate emissions of AN-fertilizer-induced N2O loss from Scottish grasslands. The increase in emissions beyond an application rate of 320 kg N/ha produced an EF of 1·74%, significantly different to that from lower application rates and much greater than the 1% default. An EF of 0·89% for urea fertilizer and 0·59% for urea with DCD suggests that N2O quantification using the IPCC default EF will overestimate emissions for grasslands where these fertilizers are applied. Large rainfall shortly after fertilizer application appears to be the main trigger for N2O emissions, thus applicability of the 1% EF could vary and depend on the weather conditions at the time of fertilizer application.

scholarly journals Weed Control in Sweet Bell Pepper Using Sequential Postdirected Applications of Pelargonic Acid

2014 ◽  
Vol 24 (6) ◽  
pp. 663-667 ◽  
Author(s):  
Charles L. Webber ◽  
Merritt J. Taylor ◽  
James W. Shrefler
Keyword(s):  
Weed Control ◽  
Sweet Pepper ◽  
Application Rate ◽  
Bell Pepper ◽  
Pelargonic Acid ◽  
Yellow Nutsedge ◽  
Crop Injury ◽  
Application Rates ◽  
Control Research ◽  
The Impact

Pepper (Capsicum annuum) producers would benefit from additional herbicide options that are safe to the crop and provide effective weed control. Research was conducted in southeastern Oklahoma (Atoka County, Lane, OK) during 2010 and 2011 to determine the impact of pelargonic acid on weed control efficacy, crop injury, and pepper yields. The experiment included pelargonic acid applied unshielded postdirected at 5, 10, and 15 lb/acre, plus an untreated weedy control and an untreated weed-free control. ‘Jupiter’ sweet bell pepper, a tobacco mosaic virus-resistant sweet pepper with a 70-day maturity, was transplanted into single rows on 3-ft centered raised beds with 18 inches between plants (9680 plants/acre) on 28 May 2010 and 27 May 2011, respectively. Weeds included smooth crabgrass (Digitaria ischaemum), cutleaf groundcherry (Physalis angulata), spiny amaranth (Amaranthus spinosus), and yellow nutsedge (Cyperus esculentus). Pelargonic acid was applied postdirected each year in mid-June and then reapplied 8 days later. The 15-lb/acre pelargonic acid treatment resulted in the maximum smooth crabgrass control (56%) and broadleaf weed control (66%) at 1 day after the initial spray treatment (DAIT), and 33% yellow nutsedge control at 3 DAIT. Pelargonic acid at 15 lb/acre provided equal or slightly greater smooth crabgrass and broadleaf (cutleaf groundcherry and spiny amaranth) control compared with the 10-lb/acre application, and consistently greater control than the 5-lb/acre rate and the weedy control. Pelargonic acid was less effective at controlling yellow nutsedge than smooth crabgrass and broadleaf weeds. As the rate of pelargonic acid increased from 5 to 15 lb/acre, yellow nutsedge control also increased significantly for all observation dates. Increasing the pelargonic acid application rate increased the crop injury rating. The maximum crop injury occurred for each application rate at 1 DAIT with 7%, 8.0%, and 13.8% injury for pelargonic acid rates 5, 10, and 15 lb/acre, respectively. There was little or no new crop injury after the second postdirected application of pelargonic acid and crop injury following 3 DAIT for application rates was 2% or less. Only the 15-lb/acre pelargonic acid application produced greater fruit per hectare (4784 fruit/ha) and yields (58.65 kg·ha−1) than the weedy control (1196 fruit/ha and 19.59 kg·ha−1). The weed-free yields (7176 fruit/ha, 178.11 kg·ha−1, and 24.82 g/fruit) were significantly greater than all pelargonic acid treatments and the weedy control. Pelargonic acid provided unsatisfactory weed control for all rates and did not significantly benefit from the sequential applications. The authors suggest the pelargonic acid be applied to smaller weeds to increase the weed control to acceptable levels (>80%).

scholarly journals Nitrogen and Rainfall Effects on Crop Growth—Experimental Results and Scenario Analyses

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2219
Author(s):  
Saadi Sattar Shahadha ◽  
Ole Wendroth ◽  
Dianyuan Ding
Keyword(s):  
Soil Water ◽  
Application Rate ◽  
Crop Growth ◽  
Water Dynamics ◽  
Nitrogen Application ◽  
Soil Water Dynamics ◽  
Application Rates ◽  
Use Efficiency ◽  
The Impact ◽  
Nitrogen Application Rate

Nitrogen (N) fertilization is critical for crop growth; however, its effect on crop growth and evapotranspiration (ETc) behaviors under different amounts of rainfall is not well understood. As such, there is a need for studying the impact of nitrogen application rates and rainfall amounts on crop growth and ETc components. Agricultural system models help to fill this knowledge gap, e.g., the Root Zone Water Quality Model (RZWQM2), which integrates crop growth-related processes. The objective of this study is to investigate the effect of the nitrogen application rate on crop growth, soil water dynamics, and ETc behavior under different rainfall amounts by using experimental data and the RZWQM2. A field study was conducted from 2016 to 2019 with three nitrogen application rates (0, 70 and 130 kg N ha−1) for unirrigated winter wheat (Triticum aestivum L.), and two nitrogen application rates (0 and 205 kg N ha−1) for unirrigated corn (Zea mays L.). For the period of 1986–2019, the amounts of actual rainfall during each crop growth period are categorized into four groups. Each rainfall group is used as a rainfall scenario in the RZWQM2 to explore the interactions between the rainfall amounts and N levels on the resulting crop growth and water status. The results show that the model satisfactorily captures the interaction effects of nitrogen application rates and rainfall amounts on the daily ETc and soil water dynamics. The nitrogen application rate showed a noticeable impact on the behavior of soil water dynamics and ETc components. The 75% rainfall scenario yielded the highest nitrogen uptake for both crops. This scenario revealed the highest water consumption for wheat, while corn showed the highest water uptake for the 100% rainfall scenario. The interaction between a high nitrogen level and 50% rainfall yielded the highest water use efficiency, while low nitrogen and 125% rainfall yielded the highest nitrogen use efficiency. A zero nitrogen rate yielded the highest ETc and lowest soil water content among all treatments. Moreover, the impacts of the nitrogen application rate on ETc behavior, crop growth, and soil water dynamics differed depending on the received rainfall amount.

scholarly journals Changing Fertilizer Management Practices in Sugarcane Production: Cane Grower Survey Insights

2020 ◽  
Author(s):  
Syezlin Hasan ◽  
James C. R. Smart ◽  
Rachel Hay ◽  
Sharyn Rundle-Thiele
Keyword(s):  
Management Practices ◽  
Negative Binomial ◽  
Fertilizer Application ◽  
Application Rate ◽  
Practice Change ◽  
Farm Income ◽  
Fertilizer Management ◽  
Application Rates ◽  
Fertilizer Application Rate ◽  
The Impact

Research focused on understanding wider systemic factors driving behavioral change is limited with a dominant focus on the role of individual farmer and psychosocial factors for farming practice change, including reducing fertilizer application in agriculture. Adopting a wider systems perspective, the current study examines change and the role that supporting services have on fertilizer application rate change. A total of 238 sugarcane growers completed surveys reporting on changes in fertilizer application along with factors that may explain behavior change. Logistic regressions and negative binomial count-data regressions were used to examine whether farmers had changed fertilizer application rates and if they had, how long ago they made the change, and to explore the impact of individual and system factors in influencing change. Approximately one in three sugarcane growers surveyed (37%) had changed the method they used to calculate fertilizer application rates for the cane land they owned/managed at some point. Logistic regression results indicated growers were less likely to change the basis for their fertilizer calculation if they regarded maintaining good relationships with other local growers as being extremely important, they had another source of off-farm income, and if they had not attended a government-funded fertilizer management workshop in the five years preceding the survey. Similar drivers promoted early adoption of fertilizer practice change; namely, regarding family traditions and heritage as being unimportant, having sole decision-making authority on farming activities and having attended up to 5 workshops in the five years prior to completing the survey. Results demonstrated the influence of government-funded services to support practice change.

scholarly journals Growth Retardant Effects on Visual Quality and Nonstructural Carbohydrates of Creeping Bentgrass

HortScience ◽  
1998 ◽  
Vol 33 (7) ◽  
pp. 1197-1199 ◽  
Author(s):  
S.W. Han ◽  
J.A Juvik ◽  
L.A. Spomer ◽  
T.W. Fermanian
Keyword(s):  
Growth Regulators ◽  
Acid Ethyl Ester ◽  
Creeping Bentgrass ◽  
Application Rate ◽  
Nonstructural Carbohydrates ◽  
Initial Application ◽  
Total Nonstructural Carbohydrates ◽  
Turf Quality ◽  
Application Rates ◽  
The Impact

Plant growth regulators are becoming important tools for managing high-quality turf. However, long-term suppression of growth might affect the potential of the turf to recuperate from summer stresses. This study was initiated to determine the impact of popular commercial turfgrass growth regulators (TGR) on the accumulation of total nonstructural carbohydrates (TNC), and their effect on turf quality. Three experiments, one each year from 1994 through 1996, were conducted on creeping bentgrass (Agrostis stolonifera Huds. `Penncross') in a greenhouse. Growth retardants evaluated included trinexapac-ethyl at 0.28 kg·ha-1, flurprimidol at 0.56 kg·ha-1, and paclobutrazol at 0.28 kg·ha-1. Each retardant was applied at three different intervals: a single initial application or multiple applications every 2 or 4 weeks, for the first 8 weeks of each experiment. The verdure and roots were harvested and analyzed for TNC. Trinexapac-ethyl, flurprimidol, and paclobutrazol significantly increased the TNC of creeping bentgrass 2 weeks after their initial application, but TNC levels began to decrease at week 4. The TNC content was strongly influenced by TGR application rate but not application intervals. A single trinexapac-ethyl application at 0.28 kg·ha-1 reduced TNC content more than did split applications, each at lower rates. Accordingly, TNC levels recovered more rapidly with lower, more frequent application rates; however, the retardation effect on vegetative growth diminished as the concentration was lowered. On the other hand, repeated low application rates of trinexapac-ethyl may have minimal effect on TNC accumulation. Chemical names used: [4(cyclopropyl-α-hydroxy-methylene)-3,5-dioxocyclohexanecarboxylic acid ethyl ester] (trinexapac-ethyl); {α-[1-methylethyl]-α-[4-(trifluoro-methoxy)phenyl]-5-pyrimidine-m ethanol}(flurprimidol);[(2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-1,2,4,-t riazole-1-yl)penta-n-3--ol] (paclobutrazol).

scholarly journals Utilização de filtro intermitente de areia como pós-tratamento de esgoto doméstico – estudo da taxa de aplicação superficial

2019 ◽  
Vol 1 (47) ◽  
pp. 95
Author(s):  
Robson Arruda Dos Santos ◽  
Gilson Barbosa Athayde Junior
Keyword(s):  
Low Cost ◽  
Application Rate ◽  
Environmental Benefits ◽  
Sand Filters ◽  
Treatment Unit ◽  
Sand Filter ◽  
Main Research ◽  
Application Rates ◽  
The Impact

<p class="Normal1">This research is the study of surface application rate for intermittent sand filter sizing, with emphasis to its constructive aspect. It is a design parameter set by the NBR 13969/1997 like the relation between the flow of sewage and surface area of a treatment unit. We examined the main research projects that studied the use of sand filter as post-treatment sewage, highlighting the superficial application rates used in these studies, comparing them with the recommendations of the Brazilian standard that deal with it. The results show that the NBR 13969/97 recommends a lower value to those obtained by Brazilian and foreigner researchers, and regarding Brazilian research, the value of the standard (100 L / m².dia) is always below the rates evaluated. Thus, we highlight the need to update the NBR 13969/97, for that would meet the actual demand for building sand filters, reactor treating of low cost of construction and maintenance, and good removal efficiency of organic matter and nitrification . The environmental benefits are indisputabl and the improvement of the quality of the effluent decreases the impact on water bodies and soil.</p>

scholarly journals Comparison of Agronomic Performance between Japonica/Indica Hybrid and Japonica Cultivars of Rice Based on Different Nitrogen Rates

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 171
Author(s):  
Tao Sun ◽  
Xin Yang ◽  
Xiaoli Tan ◽  
Kefeng Han ◽  
Sheng Tang ◽  
...  
Keyword(s):  
Grain Yield ◽  
Hybrid Rice ◽  
N Uptake ◽  
Application Rate ◽  
Growth Stages ◽  
Japonica Rice ◽  
N Application ◽  
Application Rates ◽  
N Application Rate ◽  
Indica Hybrid Rice

Previous studies have revealed that the japonica/indica hybrid rice has a higher yield potential, biomass production, and nitrogen (N) accumulation than japonica rice in China, however, at a single N application rate. It remains unclear whether it also occurs at a higher or lower N application rate under the same field condition. To investigate the effects of nitrogen application rates on grain yield, N uptake, dry matter accumulation, and agronomic N use efficiency, field experiments were conducted in Jinhua City, Zhejiang Province during three consecutive growth seasons in 2016, 2017, and 2018. Two japonica/indica hybrid varieties (Yongyou 12 and Yongyou 538) and two japonica varieties (Xiushui 134 and Jia 58) were exposed to five N application rates (0, 150, 225, 300, and 375 kg ha−1). The results showed that grain yields of all the varieties increased with increasing nitrogen application rates, except for Jia 58 whose optimum nitrogen level was 225 kg ha−1, because no significant difference was observed between N225 and N300. Across the four rice varieties, N uptake increased significantly with increased N-fertilizer rates at all the growth stages (p < 0.05). Across the three planting years, the average grain yield of japonica/indica hybrid rice was higher than that of japonica rice by 75.6% at N0, 57.2% at N150, 41.1% at N225, 38.3% at N300, and 45.8% at N375. We also found that as compared with japonica rice, the japonica/indica hybrid rice had more grain yield, higher dry matter, and higher N uptake at all growth stages, regardless of the N application rate.

A glasshouse study on the interaction of low mineral ash biochar with nitrogen in a sandy soil

Soil Research ◽  
2010 ◽  
Vol 48 (7) ◽  
pp. 569 ◽  
Author(s):  
L. van Zwieten ◽  
S. Kimber ◽  
A. Downie ◽  
S Morris ◽  
S. Petty ◽  
...  
Keyword(s):  
Microbial Activity ◽  
Biomass Production ◽  
Cropping Systems ◽  
N Uptake ◽  
Application Rate ◽  
Vegetable Production ◽  
Crop Species ◽  
N Application ◽  
Application Rates ◽  
Fertiliser Application

The effect of a low mineral ash biochar on biomass production and nitrogen (N) uptake into plants was tested with wheat and radish in a Yellow Earth used for commercial vegetable production. The biochar had an acid neutralising capacity <0.5% CaCO3, a total C content of 75%, and a molar H/C ratio of 0.45, indicating stability due to its aromaticity. A pot trial was established under climate-controlled conditions. Five rates of N fertiliser (0, 17, 44, 88, 177 kg N/ha) were applied as urea in combination with 5 biochar rates (0, 1.1, 2.2, 4.4, 11% w/w). Analysis of biomass production revealed a significant biochar × N fertiliser interaction. In particular, increasing biochar concentrations improved biomass production in both crop species at lower N application rates. The highest biochar application rate resulted in significantly greater accumulation of NO3 –-N in the soil and lower NH4 +-N averaged across the 5 N application rates. The biochar also decreased available P, and significantly increased microbial activity measured using the fluorescein diacetate method. Increasing N fertiliser application resulted in greater accumulation of NO3 –-N with no changes to NH4 +-N averaged across the 5 biochar application rates. Nitrogen fertiliser application did not influence microbial activity or biomass C. The trial suggests that in some cropping systems, biochar application will enable reduced N fertiliser input while maintaining productivity.

scholarly journals Nutrient use Efficiency in Calcareous Soil Amended by the Silicate, Humate and Compost

2021 ◽  
pp. 1-12
Author(s):  
Dalal H. Sary ◽  
Rama T. Rashad
Keyword(s):  
Calcareous Soil ◽  
Agricultural Research ◽  
Block Design ◽  
N Uptake ◽  
Nutrient Use Efficiency ◽  
Application Rate ◽  
Research Station ◽  
Application Rates ◽  
Nutrient Use ◽  
Use Efficiency

Aims: A study was carried out in the field aims to study the response of a calcareous soil cultivated by soybean to the application of K-silicate (K-Si), K-humate (K-H), and compost at application rates 50% and 100% of the recommended dose. Study Design: Complete randomized block design with three replicates. Place and Duration of Study: At El-Nubaryia Agricultural Research Station (latitude of 30° 30°N longitude of 30° 20°E) Agricultural Research Center (ARC), Nubaryia, Egypt (Summer seasons of 2018 and 2019). Methodology: Compost was mixed with surface soil a week before cultivation at application rates 3.75 and 7.5 kg plot-1 (3.91 and 7.81 t ha-1, respectively). Powder K-H was spread on soil at application rates 7.5 and 15 g plot-1 while aqueous solutions of K-Si; 8 and 16 mL L-1 for plot was sprayed on soil 30, 60, and 90 days after cultivation. Results: Results showed that soil moisture(SM, %) was increased by the 100% application rate in the order compost (20.6%) > K-Si (19.3%) > K-H (19.1%). A significant increase was found in the seed yield (kg ha-1) by 129.5%, 84.8% and 70.6% by compost, K-H and K-Si, respectively. Compost at 100% application rate showed the most significant increase in the available nitrogen N (mg kg-1) in soil by 104.4% followed by K-H (by 81.8%) then K-Si by 23.4%. Compost also showed the most significant increase in the N uptake from soil (kg ha-1 soil) by seeds and straw followed by K-H then K-Si. The nutrient use efficiency (NUE, %) and agronomic efficiency (AE) values decreased in the order K-H > K-Si > compost at 50% and 100% application rates. Conclusion: The quite smaller dose and ease of field application by spraying may make the K-H more agronomically efficient than K-Si and compost.

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