scholarly journals Corn Cropping System And Nitrogen Fertilizers Technologies Affect Ammonia Volatilization In Brazilian Tropical Soils

2021 ◽  
Author(s):  
César Ferreira Santos ◽  
Sheila Isabel do Carmo Pinto ◽  
Douglas Guelfi ◽  
Sara Dantas Rosa ◽  
Adrianne Braga da Fonseca ◽  
...  
Keyword(s):  
Ammonia Volatilization ◽  
Cropping System ◽  
Tropical Soils ◽  
Nitrogen Fertilizers ◽  
Corn Yield ◽  
N Removal ◽  
Tillage System ◽  
The Mean ◽  
N Use ◽  
T System

Abstract With the advance of the no-tillage system (NT system) in Brazil, the adoption of technologies for nitrogen fertilization in these soils become essential for increasing the efficiency of N use in the system. In this sense, the objective of this study was to quantify ammonia losses, N removal in grains, and with 2nd crop yield in NT system and conventional (T system) planting areas that received application of different N fertilizers and their technologies. Ammonia volatilization, N extraction in grains and corn yield in response to the application of conventional fertilizers were compared to urease inhibitors treated urea in NT and T systems. The treatments were: no-N (Control); Prilled urea (PU); urea + NBPT (UNBPT); urea + Cu + B (UCuB); ammonium nitrate (AN), and ammonium sulfate (AS). In the NT system, the N-NH3 losses were 49% greater than in the T system; without differences for corn yield. The fertilizers as AN, and AS had the lowest N-NH3 losses, regardless of tillage system. UNBPT reduced the mean N-NH3 loss by 33% compared to PU. UNBPT (1,200 mg kg-1) and UNBPT (180 mg kg-1) reduced by 72% and 22% the N-NH3 losses compared to PU in the NT system.

scholarly journals Diversity and Longevity of the Soybean Debris Mycobiota in a No-Tillage System

Plant Disease ◽  
1997 ◽  
Vol 81 (5) ◽  
pp. 530-534 ◽  
Author(s):  
R. E. Baird ◽  
B. G. Mullinix ◽  
A. B. Peery ◽  
M. L. Lang
Keyword(s):  
Cover Crops ◽  
Survival Rates ◽  
Fungal Species ◽  
No Tillage ◽  
Cercospora Kikuchii ◽  
Tillage System ◽  
Mesh Bags ◽  
Colletotrichum Spp ◽  
The Mean ◽  
Total Fungi

The survival of the mycobiota on pod and stem debris of soybean produced in a no-tillage system with cover crops of alfalfa, canola, rye, or wheat or with no cover was studied during 1994 and 1995. Fiberglass mesh bags containing pods and stems were assayed every 28 to 31 days to determine the isolation frequency of fungi. Over 90% of the 11,906 isolates obtained were members of the Deuteromycotina. The most common genera isolated were Alternaria, Cercos-pora, Colletotrichum, Epicoccum, Fusarium, and Phoma. Alternaria spp. had the greatest isolation frequencies and constituted 40% of the total cultures. Numbers of total fungi (all fungi isolated) on sampling dates in 1994 were similar to the totals in 1995. In May 1994, the mean isolation rates for many of the fungal species were significantly lower (P = 0.05) in several of the cover crops, but no consistent pattern could be determined. Common soybean pathogens isolated included Colletotrichum spp., Diaporthe spp., and Cercospora kikuchii. Fusarium graminearum, which is responsible for several diseases of maize and wheat, was commonly isolated during this study. Of the Diaporthe spp. (anamorph Phomopsis spp.), 87% were identified as D. phaseolorum var. sojae. Colletotrichum spp. were identified as C. truncatum in 85% of the isolates, C. destructivum (teleomorph Glomerella glycines) in 12%, and both species in 3%. Cercospora kikuchii was more commonly isolated from pods than from stem tissue, and Colletotrichum spp. occurred more frequently on stems. Isolation frequencies of Diaporthe spp. were greater in May of both years than in the preceding months. These results show that no-tillage soybean debris harbors numerous fungi pathogenic to soybean, and producers who grow soybeans continuously may find more disease in this crop and lower yields. Fungi that attack crops such as maize and wheat were commonly isolated from soybean debris in both years, and a no-tillage rotation which includes maize or wheat could result in increased disease in these crops. Isolation frequencies of the fungi from cover crops varied with the sampling date, but no consistent patterns could be determined for a particular cover crop or fungal species. This is the first detailed study of survival rates of soybean, maize, and wheat pathogens that overwinter on soybean debris in a no-tillage system.

scholarly journals Soil solution and plant nitrogen on irrigated rice under controlled release nitrogen fertilizers

2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Thais Antolini Veçozzi ◽  
Rogério Oliveira de Sousa ◽  
Walkyria Bueno Scivittaro ◽  
Cristiano Weinert ◽  
Victor Raul Cieza Tarrillo
Keyword(s):  
Controlled Release ◽  
Rice Field ◽  
Nutrient Release ◽  
Nitrogen Fertilizers ◽  
Irrigated Rice ◽  
Plant Nitrogen ◽  
Coated Urea ◽  
Use Efficiency ◽  
Polymer Coated Urea ◽  
N Use

ABSTRACT: A study was conducted to evaluate the solubilization and nitrogen (N) use efficiency (NUE) of controlled release nitrogen fertilizers in irrigated rice, compared to urea. It was developed under semi-controlled conditions, including five treatments: Control, Splitted Urea (pre-sowing and topdressing), Pre-sowing urea, and Polymer Coated Urea (PCU) with 60-day and 90-day release. PCUs did not maintain high NH4 + and NO3 - levels in solution over a longer period than urea. NUE of PCUs was similar to uncoated urea, not increasing nutrient release in irrigated rice field.

scholarly journals Association of Chocolate Spot and Faba Bean Rust Epidemics with Climate Change Resilient Cultural Practices in Bale Highlands, Ethiopia

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Gosaye Eshetu ◽  
Yekedem Bimrew ◽  
Hassen Shifa
Keyword(s):  
Faba Bean ◽  
Weed Management ◽  
Management Practices ◽  
Cultural Practices ◽  
Disease Incidence ◽  
Cropping System ◽  
Previous Crop ◽  
Multiple Variable ◽  
Chocolate Spot ◽  
The Mean

Field survey was conducted in south eastern Ethiopia to determine the disease intensity of chocolate spot and rust and to investigate the association of disease intensity (incidence and severity) with environmental factors and crop cultural practices. A total of 280 faba bean fields were surveyed in eight districts, and type of cropping system, weed management practices, crop growth stage, previous crop in the field, and sowing date were recorded. The associations of disease intensity with independent variables were evaluated using logistic regression model. Mean disease incidence of chocolate spot varied from 70.9 to 93.2% in most fields while percentage severity index (PSI) ranged from 10.5 to 47.1%. In a reduced multiple variable model, chocolate PSI ≤ 30% showed high probability of association with mixed cropping system, good weed management practices, late planting, and when faba bean was rotated with vegetables and cereals. The mean disease incidence of faba bean rust was varied from 23.6 to 78.2%, while the mean PSI of rust was varied from 4.8 to 37.9%. In Gasera, Dinsho, and Agarfa districts, poor weed management practices, fields planted in the month of July, and when previous crop was legume had a high probability of association to (>20) rust PSI in a multiple variable reduced model. In contrast, soil types, fertilizer applied, and fungicides sprayed were not associated with disease intensity. The present study has identified cropping system, planting date, previous crop, district, and weed management practices as important variables that influence faba bean chocolate spot and rust epidemics in diversified fields. Therefore, proper weeding management practices, late planting, crop rotation habit, and other related farm practices should be carried out to reduce chocolate spot and rust impact until resistant faba bean genotypes are developed and distributed to the area.

Ammonia Volatilization from Broadcast Urea and Alternative Dry Nitrogen Fertilizers

2017 ◽  
Vol 81 (6) ◽  
pp. 1629-1639 ◽  
Author(s):  
Sarah K. Del Moro ◽  
Dan M. Sullivan ◽  
Donald A. Horneck
Keyword(s):  
Ammonia Volatilization ◽  
Nitrogen Fertilizers

Nitrate pollution in groundwater and strategies to reduce pollution

2002 ◽  
Vol 45 (9) ◽  
pp. 29-35 ◽  
Author(s):  
R.K. Shrestha ◽  
J.K. Ladah
Keyword(s):  
Cropping System ◽  
Sweet Pepper ◽  
World Health ◽  
Wet Season ◽  
Tropical Ecosystem ◽  
Mineral N ◽  
Use Efficiency ◽  
Low Levels ◽  
Indigofera Tinctoria ◽  
N Use

The input-intensive rainfed tropical ecosystem, where wet season (WS) rice (Oriza sativa L.) – dry season (DS) diversified high-value upland crops like vegetables predominate, has resulted in a problem of a large leakage of N into the environment, thereby polluting the water. Excessive use of N fertilizer in high-value crops grown in DS is economically motivated. Out of twenty water sources evaluated in a watershed with a total area of 265 ha located in Magnuang, Ilocos Norte, Philippines, twelve had near or above the World Health Organization’s (WHO) NO3-N limit for drinking water of 10 ppm. Soil mineral N (upper 100 cm) observed in seven rice-sweet pepper (Capsicum annuum L.) farmers’ fields ranged from 111 to 694 kg ha-1 which decreased by 10 to 68% in plots with dry-to-wet (DTW) crops like indigo, indigo+mungo and corn. In fallow plots where mineral N was either maintained or increased, it showed movement to lower soil profiles demonstrating NO3 leaching without a crop. On average, maize (Zea mays L.) captured 176 kg N ha-1 and indigo (Indigofera tinctoria L.) 194 kg N ha-1. In both fallow and planted plots, mineral N declined to low levels at 100% water-filled pore spaces (WFPS) before rice transplanting. A strategy for including indigo plus maize as a N-catch crop is proposed to decrease NO3 leaching and maximize N use efficiency in a rice-sweet pepper cropping system.

scholarly journals Effects of cropping system and genotype on variability in important phytonutrients kontent of the barley grain for direct food use

2011 ◽  
Vol 49 (No. 10) ◽  
pp. 443-450 ◽  
Author(s):  
J. Ehrenbergerová ◽  
K. Vaculová ◽  
V. Psota ◽  
P. Havlová ◽  
V. Šerhantová
Keyword(s):  
Chemical Treatment ◽  
Cropping Systems ◽  
Starch Content ◽  
Cropping System ◽  
Barley Grain ◽  
Beta Glucan ◽  
Beta Glucans ◽  
Different Types ◽  
The Mean ◽  
Starch Composition

In a four-year period (1997–2000), selected phytonutrients, of which the beta-glucan content is most important for human health, were studied in caryopses of different types of barley varieties and lines (standard, waxy, hulless) from two cropping systems. It was significantly highest in the waxy variety Washonubet (4.93%). The whole group of waxy types of barley showed a significantly higher mean content of beta-glucans (4.75%) than the varieties with standard starch composition (4.12%), the starch content, however, was significantly higher in standard varieties (61.98%) than in waxy types (60.30%). The hulless varieties, however, had a significantly higher mean starch content (61.73%) than the hulled forms (61.07%) and a significantly higher protein content (13.82% versus 13.00%). The hulless intensive varieties and lines had a significantly higher content of beta-glucans (4.34%) and protein (13.95%) than the hulled intensive varieties (4.07%, 12.65%). Chemical treatment and fertilization increased significantly only the mean content of protein in caryopses (13.77%) compared to the variants with the absence of treatment (13.13%), the content of beta-glucans and starch increased insignificantly (by 0.12% and 0.27%). Years and varieties participated most in the variability of starch content (31.67%, 28.08%), varieties in the content of beta-glucans and protein (per 22%), and (21%) the interaction of varieties and years in the variability of these two nutrients.

Simultaneous autotrophic denitrification and nitrification in a low-oxygen reaction environment

2014 ◽  
Vol 70 (4) ◽  
pp. 729-735 ◽  
Author(s):  
Ganapathy Ramanathan ◽  
Christopher M. Sales ◽  
Wen K. Shieh
Keyword(s):  
Residence Time ◽  
Oxygen Demand ◽  
Autotrophic Denitrification ◽  
Low Oxygen ◽  
Total N ◽  
N Removal ◽  
Bioreactor System ◽  
The Mean ◽  
The Stability ◽  
Ammonia Oxidising Bacteria

The occurrence of autotrophic denitrification and nitrification activities by ammonia-oxidising bacteria and nitrite-oxidising bacteria is studied in a bioreactor system operable at low-dissolved oxygen (DO) and at variable oxygen influx rates. At a loading of 3.6 mg NH4+–N/h into the bioreactor, simultaneous autotrophic denitrification and nitrification contributed to NH4+–N removal over oxygen influxes of 2–14 mg O2/h and DO <0.5 mg/L. The maximum autotrophic denitrification (or total-N removal) rates were achieved in a narrow oxygen influx band of 3–5 mg O2/h, where it accounted for up to 36% of NH4+–N removal. At oxygen influx >16 mg O2/h and DO >2 mg/L, autotrophic denitrification ceases and roughly 90% of feed NH4+–N is oxidised to NOX−–N. The stability of total effluent chemical oxygen demand (COD) over the range of oxygen influxes tested confirms the absence of heterotrophic denitrification in the bioreactor. The long solids residence time of the stable biomass zone (21 days) led to production of effluent COD as a result of cell decay, and thus effluent COD was used to calculate more accurately the mean cell residence time.

Corn Yield as Affected by Liming and Tillage System on an Acid Brazilian Oxisol

2002 ◽  
Vol 94 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Paulo R. Ernani ◽  
Cimelio Bayer ◽  
Leonardo Maestri
Keyword(s):  
Corn Yield ◽  
Tillage System

Derterminatin of the mineralization coefficient of soil organic nitrogen on two soils at Katherine, NT

1967 ◽  
Vol 7 (26) ◽  
pp. 266 ◽  
Author(s):  
R Wetselaar
Keyword(s):  
Organic Nitrogen ◽  
Nitrate Nitrogen ◽  
Cropping System ◽  
First Year ◽  
Soil Organic Nitrogen ◽  
Legume Crop ◽  
Decomposition Constant ◽  
Nitrogen Yields ◽  
The Mean

The mineralization coefficient (M.C.) (the amount of nitrate nitrogen formed in one season in sift, by bare fallowing the soil, as a percentage of the amount of organic nitrogen in the topsoil at the onset of the season) was measured on two soils at Katherine, N.T. The determination of M.C. is regarded as useful in evaluating the 'true' decomposition constant of a soil under annual cropping conditions. Its relation to the 'apparent' decomposition constant is discussed. Tippera clay loam had a mean M.C. of 4.80 per cent, and the fluctuations around the mean were positively related to amount of rainfall. The M.C. for Blain sand dropped from 12.5 per cent in the first year of cultivation to 5.0 per cent in the third and fourth years. The data indicate that the initial high nitrogen yields on the sandy soil will in time decline to a low level unless a legume crop is incorporated in the cropping system.

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