scholarly journals Abrasive Weeding as a Vehicle for Precision Fertilizer Management in Organic Vegetable Production

2020 ◽  
pp. 1-8
Author(s):  
Tran Kim Ngan Luong ◽  
Frank Forcella ◽  
Sharon A. Clay ◽  
Michael S. Douglass ◽  
Sam E. Wortman
Keyword(s):  
Crop Yield ◽  
Organic Fertilizer ◽  
N Uptake ◽  
Application Rate ◽  
N Fertilizer ◽  
Ammonium Uptake ◽  
Fertilizer Management ◽  
Weed Biomass ◽  
Application Rates ◽  
Compost Amendment

Abrasive weeding is a nonchemical weed control tactic that uses small, gritty materials propelled with compressed air to destroy weed seedlings. Organic fertilizers have been used successfully as abrasive grits to control weeds, but the goal for this study was to explore the effects of fertilizer grit, application rates, and background soil fertility on weeds, plant available nitrogen (N) uptake, and crop yield. Field trials were conducted in organic ‘Carmen’ sweet red pepper (Capsicum annuum) and organic ‘Gypsy’ broccoli (Brassica oleracea var. italica) and treatments included organic fertilizer grit (8N–0.9P–3.3K vs. 3N–3.1P–3.3K), grit application rates (low vs. high), compost amendments (with and without), and weedy and weed-free controls. Weed biomass was harvested at 84 days and 65 days after transplanting for pepper and broccoli, respectively. Simulated total plant available N (nitrate + ammonium) uptake was measured with ion exchange resin stakes between 7 and 49 days after the first of two grit applications. Produce was harvested at maturity, graded for marketability, and weighed. The higher grit application rate, regardless of fertilizer type, reduced the weed biomass by 75% to 89% for pepper and by 86% to 99% for broccoli. By 5 weeks after the first grit application, simulated plant N uptake was greatest following grit application with the 8% N fertilizer, followed by the 3% N fertilizer, and lowest in the weedy control. The high grit application rate of 8% N fertilizer increased pepper yield by 112% compared with the weedy control, but it was similar to that of the weed-free control. Broccoli was less responsive to abrasive grits, with yield changes ranging from no difference to up to a 36% increase (relative to the weedy control) depending on the application rate and compost amendment. This is the first evidence indicating that the nutrient composition of organic fertilizer abrasive grits can influence in-season soil N dynamics, weed competition, and crop yield. The results suggest that abrasive weeding technology could be leveraged to improve the precision of in-season fertilizer management of organic crops.

scholarly journals Nitrogen Leaching and Nitrogen Balance under Differing Nitrogen Fertilization for Sugarcane Cultivation on a Subtropical Island

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 740
Author(s):  
Ken Okamoto ◽  
Shinkichi Goto ◽  
Toshihiko Anzai ◽  
Shotaro Ando
Keyword(s):  
N Uptake ◽  
Fertilizer Application ◽  
Application Rate ◽  
N Fertilizer ◽  
N Leaching ◽  
N Recovery ◽  
N Application ◽  
Fertilizer Application Rate ◽  
Sugarcane Yield ◽  
Cropping Seasons

Fertilizer application during sugarcane cultivation is a main source of nitrogen (N) loads to groundwater on small islands in southwestern Japan. The aim of this study was to quantify the effect of reducing the N fertilizer application rate on sugarcane yield, N leaching, and N balance. We conducted a sugarcane cultivation experiment with drainage lysimeters and different N application rates in three cropping seasons (three years). N loads were reduced by reducing the first N application rate in all cropping seasons. The sugarcane yields of the treatment to which the first N application was halved (T2 = 195 kg ha−1 N) were slightly lower than those of the conventional application (T1 = 230 kg ha−1 N) in the first and third seasons (T1 = 91 or 93 tons ha−1, T2 = 89 or 87 tons ha−1). N uptake in T1 and T2 was almost the same in seasons 1 (186–188 kg ha−1) and 3 (147–151 kg ha−1). Based on the responses of sugarcane yield and N uptake to fertilizer reduction in two of the three years, T2 is considered to represent a feasible fertilization practice for farmers. The reduction of the first N fertilizer application reduced the underground amounts of N loads (0–19 kg ha−1). However, application of 0 N in the first fertilization would lead to a substantial reduction in yield in all seasons. Reducing the amount of N in the first application (i.e., replacing T1 with T2) improved N recovery by 9.7–11.9% and reduced N leaching by 13 kg ha−1. These results suggest that halving the amount of N used in the first application can improve N fertilizer use efficiency and reduce N loss to groundwater.

scholarly journals Nitrogen Fate and Efficiency of Fertilizer Application under a Rapeseed–Wheat–Rice Rotation System in Southwest China

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 258
Author(s):  
Peng Ma ◽  
Yan Lan ◽  
Tengfei Lyu ◽  
Feijie Li ◽  
Zhiyuan Yang ◽  
...  
Keyword(s):  
Southern China ◽  
Fertilizer Application ◽  
Application Rate ◽  
N Fertilizer ◽  
Management Model ◽  
Fertilizer Management ◽  
Rotation System ◽  
Residual N ◽  
Rice Season ◽  
Stable Yield

To evaluate the efficient use of nitrogen (N) for rice in a rapeseed–wheat–rice rotation system, a pot experiment was conducted. The results indicated that in the conventional 15N-labeled (Nc) and reduced 15N-labeled (Nr) urea applications, absorbed N and soil residual N was higher in rapeseed than in wheat. In the rice season, the higher accumulation of 15N was achieved with an Nr application rate during the rapeseed season and an N fertilizer management model (40% as basal fertilizer, 40% as tillering fertilizer, and 20% as panicle fertilizer) during the rice season (PrNrM3). A high 15N accumulation was also achieved under the Nc application rate during the wheat season and the N fertilizer management model during the rice season (PwNcM3). The accumulation of 15N in PrNrM3 and PwNcM3 accounted for 21.35% and 36.72% of the residual N under the Nr application rate in the rapeseed season and the Nc application rate in the wheat season, respectively. Compared with the Nc application rate in the rapeseed season and M3 N management in the rice season (PrNcM3), the N agronomy efficiency (NAE) and the N partial factor efficiency (NPFP) of rice were increased by 23.85% and 1.59%, respectively, in PrNrM3. The annual crop yield was 3.95% lower in PrNrM3, which was not significant. PrNrM3 was a stable yield, N-saving application rate for rapeseed-rice rotation systems in southern China.

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 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 Evaluation of Poultry Litter and Organic Fertilizer Rate and Source for Production of Organic Short-day Onions

2010 ◽  
Vol 20 (2) ◽  
pp. 304-307 ◽  
Author(s):  
George E. Boyhan ◽  
Ray J. Hicks ◽  
Reid L. Torrance ◽  
Cliff M. Riner ◽  
C. Randell Hill
Keyword(s):  
Allium Cepa ◽  
Organic Fertilizer ◽  
Poultry Litter ◽  
N Fertilizer ◽  
Fertilizer Rate ◽  
Linear Effect ◽  
Short Day ◽  
Application Rates ◽  
N Fertilizer Rate

In a 3-year study of poultry litter applications on short-day onion (Allium cepa) production, where rates ranged from 0 to 10 tons/acre, there was an increasing linear effect on total onion yield. Jumbo (≥3 inches diameter) onion yield did not differ with increasing poultry application rates, while medium (≥2 and <3 inches diameter) yields decreased with increasing applications of poultry litter. In addition, organic-compliant fertilizers, 4N–0.9P–2.5K at 150 to 250 lb/acre nitrogen (N), as well as 13N–0P–0K at 150 lb/acre N and in combination with 9N–0P–7.5K totaling 150 lb/acre N were evaluated. Comparison of these commercial organic-compliant fertilizers indicated that there were no differences in total or jumbo yields, while medium yields generally decreased with increased N fertilizer rate.

Effect of fertilizer rate and form on the recovery of 15N-labelled fertilizer applied to wheat in Syria

1997 ◽  
Vol 128 (4) ◽  
pp. 415-424 ◽  
Author(s):  
C. J. PILBEAM ◽  
A.M. McNEILL ◽  
H. C. HARRIS ◽  
R. S. SWIFT
Keyword(s):  
Fertilizer Application ◽  
Application Rate ◽  
N Fertilization ◽  
N Fertilizer ◽  
Organic N ◽  
Inorganic N ◽  
Fertilizer Rate ◽  
Application Rates ◽  
Dry Conditions ◽  
Added Nitrogen Interaction

15N-labelled fertilizer was applied at different rates (0, 30, 60, 90 kg N ha−1) and in different forms (urea or ammonium sulphate) to wheat grown in Syria in three seasons (1991/92, 1992/93 and 1994/95).Recovery of 15N-labelled fertilizer in the above-ground crop at harvest was low (8–22%), with the amount of 15N-labelled fertilizer recovered in the crop increasing as the rate of application increased. Fertilizer application caused a significant increase in the amount of unlabelled soil N in the crop, suggesting that the application of N fertilizer caused a ‘real’ added nitrogen interaction. Recovery of 15N-labelled fertilizer in the crop was unaffected by the form of the fertilizer.On average 31% (14–54%) of the 15N-labelled fertilizer remained in the soil at harvest, mostly in the 0–20 cm layer. At the lowest application rate (30 kg N ha−1) most of the residual fertilizer was as organic N, but at the higher application rates (60 and 90 kg N ha−1), a greater proportion of the 15N-labelled fertilizer was recovered as inorganic N, presumably as the result of top-dressing N in dry conditions in the spring. The amount of 15N-labelled fertilizer remaining in the soil increased as the fertilizer rate increased, but was unaffected by the form of fertilizer applied.Losses of 15N-labelled fertilizer were large (>35%), probably caused by gaseous losses, either through volatilization of N from the calcareous soil, or through denitrification from wet soils rich in organic residues.N fertilization strategies in the West Asia/North Africa (WANA) region should take note of the low recovery of N fertilizer by the crop in the season of application, and the resultant large quantities of residual fertilizer.

No-tillage culture and nitrogen fertilizer management for burley tobacco production

2016 ◽  
Vol 155 (4) ◽  
pp. 599-612 ◽  
Author(s):  
C. ZOU ◽  
R. C. PEARCE ◽  
J. H. GROVE ◽  
M. S. COYNE
Keyword(s):  
N Uptake ◽  
N Fertilization ◽  
N Fertilizer ◽  
No Tillage ◽  
Fertilizer Management ◽  
Fertilizer Rate ◽  
Burley Tobacco ◽  
Tobacco Production ◽  
N Fertilizer Rate

SUMMARYFew studies have investigated nitrogen (N) fertilizer management in no-tillage (NT) tobacco (Nicotiana tobacumL.) production systems, even though N fertilization is known to influence tobacco cured leaf yield and quality. The present study evaluated how tillage practice and N fertilizer rate affected burley tobacco agronomic performance, plant available nitrogen (PAN) supply, and leaf chemical constituents. In 2012 and 2013, three N fertilizer rates (0, 140 and 280 kg N/ha) were introduced as split-plots within a long-term NT and conventional tillage (CT) (mouldboard plough) comparison study. Results (2007–2013) showed that the effect of tillage on tobacco yield depended on seasonal weather; NT tobacco appeared to have lower yield than CT tobacco in seasons with <450 mm growing season rainfall, but similar yields when rainfall was >500 mm. In 2012 (432 mm rainfall; 84% of the long-term seasonal mean), leaf SPAD reading, leaf nitrate concentration, total nitrogen concentration at the topping day (i.e. removal of flowers/buds at the tops of the plants) and cured leaf nicotine and alkaloid content suggested that N deficiency was more pronounced in NT than CT at the lowest N fertilizer rate. The PAN supply, as measured by a modifiedin situresin core method, was similar in 2012 between NT and CT, suggesting that plant factors may have had a role in N uptake efficiency. This scenario did not repeat in 2013 (706 mm rainfall; 137% of the long-term seasonal mean). Even though N fertilization rates were identical for both tillage practices in 2012 and 2013, PAN was lower, on average, in 2012. Because N uptake is largely the result of mass flow, the impact of reduced root density in NT tobacco would be expected to be more pronounced in a season such as 2012, when water was limited. Banding N close to the tobacco root system and/or side-dressing some portion of N may be recommended strategies to improve N use efficiency in NT burley tobacco production.

Dry matter production by a subtropical grass (Makarikari grass) grown in association with a temperate annual legume (barrel medic) and nitrogen fertilizer in southern Queensland

1985 ◽  
Vol 25 (1) ◽  
pp. 54 ◽  
Author(s):  
DL Lloyd ◽  
TB Hilder
Keyword(s):  
Dry Matter ◽  
N Uptake ◽  
Winter Season ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Pasture Grass ◽  
Barrel Medic ◽  
Application Rates ◽  
Matter Production ◽  
Cutting Experiment

The effects of a temperate annual legume, barrel medic (Medicago truncatula) cv. Cyprus, and five levels of fertilizer nitrogen (N), from 0 to 400 kg/ha.year, on the dry matter (DM) production and N economy of Makarikari grass (Panicum coloratum var. makarikariense) cv. Pollock, were investigated in a cutting experiment between 1973 and 1979. Each year, N fertilizer on grass alone increased both DM production and N uptake, up to N application rates of 200 and 400 kg/ha.year respectively. The mean annual effect of medic was to increase DM production and N uptake of associated grass each year by 90 and 130% respectively, and of the grass-medic system by 230 and 530%, respectively, for fertilizer rates between 0 and 100 kg N/ha.year. The increased DM production of associated grass occurred in summer and autumn; grass DM production was suppressed in spring, probably by competition with the medic. A trend for the DM yield of grass grown without medic to decline with time was most evident in the treatment without N fertilizer; in the comparable grass-medic pasture, grass DM production was as great in the sixth year as in the first. Medic DM yield varied with winter season rainfall. When the study concluded, the amount of N in the soil (0-10 cm depth) was higher after grassmedic than grass alone, except at the highest level of N fertilizer application. It was estimated that medic had fixed about 71 kg N/ha.year.

scholarly journals Optimizing nitrogen fertilizer use for more grain and less pollution

2021 ◽  
Author(s):  
Keyu Ren ◽  
Minggang Xu ◽  
Rong Li ◽  
Lei Zheng ◽  
Shaogui Liu ◽  
...  
Keyword(s):  
Crop Production ◽  
Management Practices ◽  
Application Rate ◽  
N Fertilizer ◽  
N Application ◽  
Fertilizer Use ◽  
Application Rates ◽  
Operational Practices ◽  
N Management ◽  
N Fertilizer Use

Abstract Optimal nitrogen (N) management is critical for efficient crop production and agricultural pollution control. However, it is difficult to implement advanced management practices on smallholder farms due to a lack of knowledge and technology. Here, using 35,502 on-farm fertilization experiments, we demonstrated that smallholders in China could produce more grain with less N fertilizer use through optimizing N application rate. The yields of wheat, maize and rice were shown to increase between 10% and 19% while N application rates were reduced by 15–19%. These changes resulted in an increase in N use efficiency (NUE) by 32–46% and a reduction in N surplus by 40% without actually changing farmers’ operational practices. By reducing N application rates in line with official recommendations would not only save fertilizer cost while increasing crop yield, but at the same time reduce environmental N pollution in China. However, making progress towards further optimizing N fertilizer use to produce more grain with less pollution would require managements to improve farmers’ practices which was estimated to cost about 11.8 billion US dollars to implement.

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