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A proposed mechanism for the volatilization of ammonia from fertilized neutral to alkaline soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, R. du T. Burger --- Department of Soil Science,Ammonia volatilization from five soils, ranging in clay content from 7,6 to 49,9%, were determined after pH values of the soils were adjusted to 8,0. Ammonium sulphate, limestone ammonium nitrate, urea, monoammonium phosphate and diammonium phosphate were applied on the... -
Laboratory measurements of ammonia volatilization from five nitrogen-containing fertilizers after surface application at different rates on a neutral to alkaline soil
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, Republic of South Africa R. du T. Burger --- Department of Soil Science, Republic of South AfricaVolatilization losses of NH3 from five fertilizers, namely (NH4)2SO4, LAN, urea, MAP and DAP were determined. The fertilizers were applied to a Bainsvlei soil of which the pH was adjusted to 6,5; 7,6; 8,3 and 9,1. The application levels were... -
Nitrogen losses from urea, UAN and LAN when applied to four different soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. D.P. Botha --- , Republic of South AfricaNitrogen transformations and losses from three nitrogenous fertilizers, urea, urea ammonium nitrate (UAN) and limestone ammonium nitrate (LAN), when applied to four South African soils, were compared in a laboratory study. The highest losses on all these soils were experienced... -
Effect of application methods on ammonia volatilization from soils in a controlled environment
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: C.C. du Preez --- Department of Soil Science, Republic of South Africa R. du T. Burger --- Department of Soil Science, Republic of South AfricaThe objective of this investigation was to compare different application methods whereby ammonia losses from nitrogen fertilizers can be limited when applied to alkaline soils. Three application methods were simulated, namely broadcasting, ploughing under and band placement. Five nitrogen fertilizers,... -
Ammonia volatilization and denitrification losses from commercial fertilizers applied to soil samples
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: A. D.P. Botha --- , Republic of South Africa D.C. Pretorius --- , Republic of South AfricaNitrogen losses from nine nitrogen fertilizers, applied to four different topsoil samples, were compared in the laboratory. Total N losses were determined 28 days after application, as a difference between the extractable soil nitrogen initially and after 28 days. The... -
The volatilization of formulated ester, amine and K salt derivatives of phenoxyalkanoic herbicides: Evidence to connect herbicide activity with plant nutrient status of tomato (Lycopersicon esculentum Mill) plants
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: R.J. Bennet --- Department of Agriculture and Water Supply, Republic of South AfricaControlled environment studies were conducted involving different vapour treatments applied to tomato plants using the herbicides 2,4-D iso-octyl ester/ioxynil, 2,4-D dimethyl amine salt and MCPA K salt. These indicated that the amine salt and MCPA were much less volatile than... -
Urease-aktiwiteite in gronde van die sentrale besproeiingsgebiede in Suid-Afrika
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: F. P.J. Thormählen --- Departement van Grondkunde, Republiek van Suid-Afrika C.C. du Preez --- Departement van Grondkunde, Republiek van Suid-AfrikaDie oogmerk met die studie was om die omvang van urease-aktiwiteite in die besproeide gronde vas te stel en watter grondparameters dit beïnvloed. Die verloop van hidrolise is in agt gronde, afkomstig van die sentrale besproeiingsgebiede, gemonitor na toediening van... -
Effek van ureumkonsentrasies op die urease-aktiwiteite in gronde van die sentrale besproeiingsgebiede in Suid-Afrika
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: F. P.J. Thormählen --- Departement van Grondkunde, Republiek van Suid-Afrika C.C. du Preez --- Departement van Grondkunde, Republiek van Suid-AfrikaDie oogmerk met die studie was om vas te stel by watter ureumkonsentrasies die urease In die besproeide gronde versadlg of geinhibeer word. Die verloop van hldrolise is In ses gronde met verskillende urease-aktiwi- teite gemonitor na toediening van ureum... -
Response of maize to ammonium nitrate, urea and cogranulated urea-urea phosphate
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: O.A. Yerokun --- Department of Soil Science, ZambiaUrea fertilizers may lose N by ammonia volatilization when applied in the field. In order to reduce this loss, modified urea compounds are being used. Not all of them reduce ammonia loss and improve crop yields. A field study was... -
Ammonia volatilization from ammonium nitrate, urea and urea phosphate fertilizers applied to alkaline soils
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: O.A. Yerokun --- Department of Soil Science, ZambiaThe volatilization of ammonia following applications of urea fertilizers to soils may release significant amounts of N into the atmosphere and reduce the plant available N. This study compared ammonia loss from urea phosphate (170 g N kg−1, 190 g...