Nitrification of urea and its loss through volatilization of ammonia under different soil conditions

1960 ◽  
Vol 55 (1) ◽  
pp. 47-51 ◽  
Author(s):  
A. Wahhab ◽  
Mahmud Khan ◽  
M. Ishaq

Nitrification of urea and its loss through the volatilization of NH3 were studied under different soil conditions. Under all conditions less urea was nitrified and more time was needed for its nitrification in sandy than in sandy loam soil. Nitrification was favoured at lower concentration of urea, onethird moisture of the moisture-holding capacity and at neutrality or the alkaline pH.Loss of NH3 was found to be twice as much from the sandy loam as from the sandy soil. It was also found that half of the total loss occurred during first drying. Loss of NH3 from urea was found to be proportional to its concentration. The loss increased with the increase in soil moisture and temperature; but it decreased with the decrease in pH on the acid side and the increase in depth of its placement.

2001 ◽  
Vol 81 (1) ◽  
pp. 45-52 ◽  
Author(s):  
R H Azooz ◽  
M A Arshad

In areas of the northwestern Canadian Prairies, barley and canola are grown in a short growing season with high rainfall variability. Excessively dry soil in conventional tillage (CT) in dry periods and excessively wet soil in no-tillage (NT) in wet periods could cause a significant decrease in crop production by influencing the availability of soil water. The effects of CT, NT and NT with a 7.5-cm residue-free strip on the planting rows (NTR) on soil water drying (–dW/dt) and recharge (dW/dt) rates were studied in 1992 and 1993 during wet and dry periods to evaluate the impact of NTR, NT and CT systems on soil moisture condition. The soils, Donnelly silt loam and Donnelly sandy loam (both Gray Luvisol) were selected and soil water content by depth was measured by time domain reflectometry. Water retained at 6 matric potentials from –5 to –160 kPa were observed. In the field study, –dW/dt was significantly greater in CT than in NT in the silt loam for the 0- to 30-cm layer during the first 34 d after planting in 1992. The 0- to 30-cm soil layer in CT and NTR dried faster than in NT during a period immediately following heavy rainfall in the silt loam in 1993. The drying coefficient (–Kd ) was significantly greater in CT and NTR than in NT in the silt loam soil in 1993 and in the sandy loam soil in 1992 in the top 30-cm depth. The recharge coefficient (Kr) was significantly greater in NT and NTR than in CT for the silt loam soil. The NTR system increased the –dW/dt by 1.2 × 10-2 to 12.1 × 10-2 cm d-1 in 1992 and 1993 in the silt loam soil and by 10.2 × 10-2 cm d-1 in 1993 in the sandy loam soil as compared with NT. The dW/dt was 8.1 × 10-2 cm d-1 greater in NTR in 1992 and 1993 in the silt loam soil and was 1.9 × 10-2 greater in NTR in 1992 than in CT in the sandy loam soil. The laboratory study indicated that NT soils retained more water than the CT soils. The NTR practice maintained better soil moisture conditions for crop growth than CT in dry periods than NT in wet periods. Compared with NT, the NTR avoided prolonged near-saturated soil conditions with increased soil drying rate under extremely wet soil. Key words: Water drying, water recharge, water depletion, wet and drying periods, hydraulic properties, soil capacity to retain water


2020 ◽  
Vol 18 (4) ◽  
pp. 84-87
Author(s):  
Yu.V. Leonova ◽  
◽  
T.A. Spasskaya ◽  

The change in the microbiological activity of sod-podzolic sandy loam soil when using coffee waste and sewage sludge as a fertilizer for oats in comparison with traditional fertilizers is considered. During the study, it was determined that the predominant groups were bacteria and actinomycetes. Bacilli and fungi are few in number. The introduction of sewage sludge and coffee waste into the sod-podzolic sandy loam soil at a dose of 10 t / ha increases the activity of the microflora of the sod-podzolic sandy loam soil, which increases the effective and potential fertility.


2016 ◽  
Vol 11 (2) ◽  
pp. 49-60
Author(s):  
David Lomeling ◽  
Juma L.L. Yieb ◽  
Modi A. Lodiong ◽  
Mandlena C. Kenyi ◽  
Moti S. Kenyi ◽  
...  

HortScience ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Salvadore J. Locascio ◽  
George J. Hochmuth ◽  
Fred M. Rhoads ◽  
Steve M. Olson ◽  
Alan G. Smajstrla ◽  
...  

Tomato (Lycopersicon esculentum Mill.) was grown with drip irrigation on an Arredondo fine sand and on an Orangeburg fine sandy loam to evaluate the effect of N and K time of application on petiole sap, leaf-N and -K concentrations, fruit yield, and to determine N and K sufficiency ranges in leaf tissue. On the sandy soil, N—K at 196-112 kg·ha-1 were applied 0%, 40%, or 100% preplant with the remainder applied in 6 or 12 equal or in variable applications in 12 weeks. With the variable application rate, most nutrients were applied between weeks 5 and 10 after transplanting. On the sandy loam soil that tested high in K, only N (196 kg·ha-1) was applied as above. Petiole sap K concentration declined during the season, but was not greatly affected by treatment. Petiole NO3-N concentrations decreased during the season from 1100 to 200 mg·L-1, and the decrease was greater with preplant N treatments. On the sandy soil, marketable fruit yields were lowest with 100% preplant, intermediate with 100% drip applied (no preplant N), and highest with 40% preplant and 60% drip applied. With 100% drip applied, yields were higher with 12 even applications than with either six even weekly applications or with 12 variable N and K applications. With 40% preplant, timing of application had little effect on yield. On the sandy loam soil in 1993, yields were highest with 100% preplant, intermediate with 40% preplant and 60% drip applied, and lowest with all N drip applied. In 1994 when excessive rains occurred, yields were similar with all preplant and with split N applications. Petiole N concentration was correlated with tomato yield, especially at 10 weeks after transplanting. The best correlation between sap-N and total yields occurred between 4 and 6 weeks at Gainesville and between 4 and 10 weeks at Quincy.


1959 ◽  
Vol 39 (1) ◽  
pp. 12-19
Author(s):  
S. J. Bocrget

Gypsum moisture blocks were calibrated in the laboratory in undisrupted soil cores, in soil cores which had been repacked to field density, and in unpacked soil baskets. Three soil types were used. It was found that the calibration curves obtained in the repacked soil cores and in the soil baskets were different from those obtained in the undisrupted soil cores. This indicates that the disruption of both structure and bulk density influenced the calibration of gypsum blocks. The effects were greater on the fine textured than on the coarse textured soils. The influence of bulk density was not important on a sandy loam soil. The variations in soil moisture obtained ranged from 1 to 6 per cent within the available water range.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1334
Author(s):  
Niharika Rahman ◽  
Catarina Henke ◽  
Patrick J. Forrestal

The efficacy of the new nitrification inhibitor 3,4 dimethylpyrazol succinic acid (DMPSA) was tested with calcium ammonium nitrate (CAN) and ammonium sulphate (AS) fertilisers in an incubation experiment using a sandy loam soil and a sandy textured soil. The experiment was conducted over 80 days. For AS fertiliser, inclusion of DMPSA resulted in significantly less NO3−-N present after 19 days in both soils. In the case of CAN, inclusion of DMPSA resulted in significantly less NO3−-N present after 45 days in the sandy loam soil and after 30 days in the sandy soil. DMPSA is effective nitrification inhibitor when combined with CAN and AS, with a mean reduction of 61% and 58%, respectively, in the average daily nitrification rate over the study period. Over the 80-day incubation period in the sandy loam soil, only 35% NH4+-N was converted to NO3−-N for AS + DMPSA compared to 88% for AS. In the sandy soil, 92% NH4+-N was converted to NO3−-N for AS compared with only 9% for AS + DMPSA by day 80. The results demonstrate that DMPSA is an effective nitrification inhibitor when combined with CAN and AS.


2004 ◽  
Vol 142 (6) ◽  
pp. 617-627 ◽  
Author(s):  
M. TRYDEMAN KNUDSEN ◽  
H. HAUGGAARD-NIELSEN ◽  
B. JØRNSGÅRD ◽  
E. STEEN JENSEN

Mixed intercropping of spring barley (Hordeum vulgare L.) with field pea (Pisum sativum L.), faba bean (Vicia faba var. minor L.) or narrow-leafed lupin (Lupinus angustifolius L.) was compared with sole cropping in two field experiments at different locations, on a sandy loam soil and a sandy soil, in Denmark in 2001.Grain legumes were dominant in intercrops on the sandy loam soil, except for lupin, whereas barley was dominant in intercrops on the sandy soil site. Combined intercrop grain yields were comparable to grain yields of the respective sole cropped grain legume or sole cropped, fertilized barley on each soil site. On the sandy loam soil, pea–barley and faba bean–barley intercrops increased the proportion of plant N derived from N2 fixation in grain legumes and increased the barley grain N concentration (from 1·7 to 2·2 mg/g) compared with sole cropping. However, the later maturity of faba bean compared with barley caused problems at harvest. The grain N concentration of intercropped barley was increased where grain legumes were the dominant intercrops and not on the sandy soil site. Lupin-barley intercrops did not show intercropping advantages to the same degree as faba bean and pea, but lupin constituted a more stable yield proportion of the combined intercrop yield over locations.Furthermore, the study indicated that the natural 15N abundance at certain locations might not always be sufficient to ensure a reliable estimate of N2 fixation using the 15N natural abundance method.


2014 ◽  
Vol 28 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Eric P. Westra ◽  
Dale L. Shaner ◽  
Philip H. Westra ◽  
Phillip L. Chapman

Pyroxasulfone dissipation and mobility in the soil was evaluated and compared toS-metolachlor in 2009 and 2010 at two field sites in northern Colorado, on a Nunn fine clay loam, and Olney fine sandy loam soil. Pyroxasulfone dissipation half-life (DT50) values varied from 47 to 134 d, and those ofS-metolachlor ranged from 39 to 63 d. Between years, herbicide DT50values were similar under the Nunn fine clay loam soil. Under the Olney fine sandy loam soil, dissipation in 2009 was minimal under dry soil conditions. In 2010, under the Olney fine sandy loam soil,S-metolachlor and pyroxasulfone had half-lives of 39 and 47 d, respectively, but dissipation rates appeared to be influenced by movement of herbicides below 30 cm. Herbicide mobility was dependent on site-year conditions, in all site-years pyroxasulfone moved further downward in the soil profile compared toS-metolachlor.


2012 ◽  
Vol 482-484 ◽  
pp. 372-375 ◽  
Author(s):  
Jing Cai Wang ◽  
Zi Qiang Xia ◽  
Ji Xing Wang ◽  
Zhi Hua Lu

An in situ field test with three indices of stability, sensitivity and accuracy on 12 soil moisture sensors was carried out in a sandy loam soil located in Lu’an at the subtropical monsoon climate region (China). The results showed that the majority of sensors were above 0.98 with a higher stability degree except for HT-DR-601(0.348) and DZN3 (0.661). Almost all sensors had a sensitive response to a certain amount of precipitation but Hydra Probe II was an exception. Trime-pico, SM300, ML2X, SWR6 and DH-FDR had a higher accuracy than 0.785, while DZN3 and HT-DR-601 were very lower. The mean differences of SM300, Trime-pico and Uni_SM were between -1% and 0, while HTSMS-02, DH-FDR, SWR6, ML2X, MP-4C and MP-323 were between -5% and -1%. DZN3 had the largest values of -17.8%. Finally, SM300, Trime-pico, ML2X, SWR6 and DH-FDR were got scores above 9 points while MP-323 and Uni_SM were above 8.4, showing an outstanding performance. The field performance study could provide some choices for the large-scale filed applications and the drought monitoring system.


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