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M Zaman - One of the best experts on this subject based on the ideXlab platform.
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effects of the different rates of urease and nitrification inhibitors on gaseous emissions of ammonia and nitrous oxide nitrate leaching and Pasture Production from urine patches in an intensive grazed Pasture system
Agriculture Ecosystems & Environment, 2010Co-Authors: M Zaman, J D BlennerhassettAbstract:Abstract Minimizing nitrogen (N) losses via ammonia (NH 3 ) and nitrous oxide (N 2 O) emissions into the atmosphere and nitrate (NO 3 − ) leaching into surface and ground waters from intensively grazed Pastures is essential for environmental protection worldwide. Applying urease inhibitor such as N-(n-butyl) thiophosphoric triamide (nBPT) or (Agrotain) and nitrification inhibitor dicyandiamide (DCD) to grazed Pastures has the potential to mitigate such N losses. A lysimeter/mini plot experiment, using Paparua silt loam soil near Lincoln, Canterbury New Zealand, was conducted to quantify these N losses during May 2007 to July 2008. The nine treatments were: cow urine only applied at an equivalent rate of 600 kg N ha −1 , urine + DCD at 5 kg ha −1 , urine + DCD at 7 kg ha −1 , urine + DCD at 10 kg ha −1 , urine + double inhibitor (DI), i.e. both Agrotain and DCD applied at 1 L ha −1 and 7 kg ha −1 , respectively (or 1:7 of v/w basis), urine + DI (1:10), urine + DI (2:7), urine + DI (2:10) and the control (no urine). These treatments were randomly applied to one set of lysimeters or mini plots in May as autumn and then to another set of lysimeters or mini plots in August as spring applications. Additional nine lysimeters received DCD only at rates equivalent to 5, 7 and 10 kg ha −1 in autumn to see if DCD has any effect on NO 3 − leaching and Pasture Production and N uptake from non-urine patches in autumn. Gaseous emissions of NH 3 and N 2 O, NO 3 − leaching and Pasture Production and N uptake varied with the types and rates of the applied inhibitors during the two seasons. DCD applied at 7 and 10 kg ha −1 rates with urine was more effective than its lower rate of 5 kg ha −1 and reduced N 2 O emissions by 37–53% (autumn) and 47% (spring), NO 3 − leaching losses by 57–55% (autumn) and 26–10% (spring) compared with urine alone. However DCD increased NH 3 emissions by 41% and 18% compared with urine alone treatment after autumn and spring, respectively. DCD applied at higher rates also increased Pasture dry matter by 9% and 12% and N uptake by 12% and 6% after autumn and spring applications, respectively. However DCD applied at different rates without urine in autumn had no such effect on either NO 3 − leaching or Pasture dry matter yield or N uptake. The DI at 1:7 ratio was more effective than the higher rates of DI and DCD in reducing losses of NH 3 (48% and 51%), N 2 O (55% and 63%) and NO 3 − leaching (56% and 42%) as well as increasing Pasture Production (13% and 17%) and N uptake (7% and 18%) compared with urine alone treatment in autumn and spring, respectively. These results suggest that applying Agrotain + DCD at a ratio of 1:7 (v/w) may provide the best option for both mitigating N losses and improving Pasture Production in intensively grazed systems.
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effect of urease and nitrification inhibitors on n transformation gaseous emissions of ammonia and nitrous oxide Pasture yield and n uptake in grazed Pasture system
Soil Biology & Biochemistry, 2009Co-Authors: M Zaman, J D Blennerhassett, S Saggar, Jatinder SinghAbstract:Abstract Nitrogen (N) losses via nitrate (NO 3 − ) leaching, ammonia (NH 3 ) volatilization and nitrous oxide (N 2 O) emissions from grazed Pastures in New Zealand are one of the major contributors to environmental degradation. The use of N inhibitors (urease and nitrification inhibitors) may have a role in mitigating these N losses. A one-year field experiment was conducted on a permanent dairy-grazed Pasture site at Massey University, Palmerston North, New Zealand to quantify these N losses and to assess the effect of N inhibitors in reducing such losses during May 2005–2006. Cow urine at 600 kg N ha −1 rate with or without urease inhibitor N-(n-butyl) thiophosphoric triamide (nBTPT) or (trade name “Agrotain”) (3 L ha −1 ), nitrification inhibitor dicyandiamide (DCD) (7 kg ha −1 ) and the use of double inhibitor (DI) containing a combination of both Agrotain and DCD (3:7) were applied to field plots in autumn, spring and summer. Pasture Production, NH 3 and N 2 O fluxes, soil mineral N concentrations, microbial biomass C and N, and soil pH were measured following the application of treatments during each season. All measured parameters, except soil microbial biomass C and N, were influenced by the added inhibitors during the three seasons. Agrotain reduced NH 3 emissions over urine alone by 29%, 93% and 31% in autumn, spring and summer respectively but had little effect on N 2 O emission. DCD reduced N 2 O emission over urine alone by 52%, 39% and 16% in autumn, spring and summer respectively but increased NH 3 emission by 56%, 9% and 17% over urine alone during those three seasons. The double inhibitor reduced NH 3 by 14%, 78% and 9% and N 2 O emissions by 37%, 67% and 28% over urine alone in autumn, spring and summer respectively. The double inhibitor also increased Pasture dry matter by 10%, 11% and 8% and N uptake by the 17%, 28% and 10% over urine alone during autumn, spring and summer respectively. Changes in soil mineral N and pH suggested a delay in urine-N hydrolysis with Agrotain, and reduced nitrification with DCD. The combination of Agrotain and DCD was more effective in reducing both NH 3 and N 2 O emissions, improving Pasture Production, controlling urea hydrolysis and retaining N in NH 4 + form. These results suggest that the combination of both urease and nitrification inhibitors may have the most potential to reduce N losses if losses are associated with urine and improve Pasture Production in intensively grazed systems.
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reducing nh3 n2o and text no _3 n losses from a Pasture soil with urease or nitrification inhibitors and elemental s amended nitrogenous fertilizers
Biology and Fertility of Soils, 2008Co-Authors: M Zaman, M L Nguyen, J D Blennerhassett, B F QuinAbstract:A 3-month field experiment comparing nitrogen (N) losses from and the agronomic efficiency of various N fertilizers was conducted on a sandy loam (Typic Hapludand) soil at Ruakura AgResearch farm, Hamilton, New Zealand during October to December 2003. Three replicates of seven treatments: urea, urea + the urease inhibitor N-(n-butyl) thiophosphoric triamide (trade name Agrotain), urea + Agrotain + elemental sulphur (S), urea + double inhibitor [DI; i.e., Agrotain + dicyandiamide (DCD)], diammonium phosphate (DAP), DAP + S, each applied at 150 kg N ha−1, and control (no N). After fertilizer application, soil ammonium (\( \operatorname{NH} ^{ + }_{4} \)) and nitrate (\( \operatorname{NO} ^{ - }_{3} \)) concentrations (7.5-cm soil depth), ammonia (NH3) volatilization, nitrate (\( \operatorname{NO} ^{ - }_{3} \)) leaching, nitrous oxide (N2O) emission, Pasture dry matter, and N uptake were monitored at different timings. Urea applied with Agrotain or Agrotain + S delayed urea hydrolysis and released soil \( \operatorname{NH} ^{ + }_{4} \) at a slower rate than urea alone or urea + DI. Urea applied with DI increased NH3 volatilization by 29% over urea alone, while urea + Agrotain and urea + Agrotain + S reduced NH3 volatilization by 45 and 48%, respectively. Ammonia volatilization losses from DAP were lower than those from urea with or without inhibitors. Total reduction in \( \operatorname{NO} ^{ - }_{3} \) leaching losses for urea + DI and urea + Agrotain compared to urea alone were 89% and 47%, respectively. Application of S with urea + Agrotain reduced \( \operatorname{NO} ^{ - }_{3} \) leaching losses by an additional 6%. Nitrous oxide emissions were higher from the DAP and urea alone treatments. Urea applied with DI and urea + Agrotain reduced N2O emissions by 37 and 5%, respectively, over urea alone. Compared to urea alone, total Pasture Production increased by 20, 17, and 15% for urea + Agrotain + S, urea + Agrotain, and urea + DI treatments, respectively, representing 86, 71, and 64% increases in N response efficiency. Total N uptake in urea + Agrotain, urea + Agrotain + S, and urea + DI increased by 29, 22, and 20%, respectively, compared to urea alone. These results suggest that the combination of both urease and nitrification inhibitors may have the most potential to reduce N losses and improve Pasture Production in intensively grazed systems.
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reducing nh 3 n 2 o and text no _3 n losses from a Pasture soil with urease or nitrification inhibitors and elemental s amended nitrogenous fertilizers
Biology and Fertility of Soils, 2008Co-Authors: M Zaman, M L Nguyen, J D Blennerhassett, B F QuinAbstract:A 3-month field experiment comparing nitrogen (N) losses from and the agronomic efficiency of various N fertilizers was conducted on a sandy loam (Typic Hapludand) soil at Ruakura AgResearch farm, Hamilton, New Zealand during October to December 2003. Three replicates of seven treatments: urea, urea + the urease inhibitor N-(n-butyl) thiophosphoric triamide (trade name Agrotain), urea + Agrotain + elemental sulphur (S), urea + double inhibitor [DI; i.e., Agrotain + dicyandiamide (DCD)], diammonium phosphate (DAP), DAP + S, each applied at 150 kg N ha−1, and control (no N). After fertilizer application, soil ammonium ( $$ \operatorname{NH} ^{ + }_{4} $$ ) and nitrate ( $$ \operatorname{NO} ^{ - }_{3} $$ ) concentrations (7.5-cm soil depth), ammonia (NH3) volatilization, nitrate ( $$ \operatorname{NO} ^{ - }_{3} $$ ) leaching, nitrous oxide (N2O) emission, Pasture dry matter, and N uptake were monitored at different timings. Urea applied with Agrotain or Agrotain + S delayed urea hydrolysis and released soil $$ \operatorname{NH} ^{ + }_{4} $$ at a slower rate than urea alone or urea + DI. Urea applied with DI increased NH3 volatilization by 29% over urea alone, while urea + Agrotain and urea + Agrotain + S reduced NH3 volatilization by 45 and 48%, respectively. Ammonia volatilization losses from DAP were lower than those from urea with or without inhibitors. Total reduction in $$ \operatorname{NO} ^{ - }_{3} $$ leaching losses for urea + DI and urea + Agrotain compared to urea alone were 89% and 47%, respectively. Application of S with urea + Agrotain reduced $$ \operatorname{NO} ^{ - }_{3} $$ leaching losses by an additional 6%. Nitrous oxide emissions were higher from the DAP and urea alone treatments. Urea applied with DI and urea + Agrotain reduced N2O emissions by 37 and 5%, respectively, over urea alone. Compared to urea alone, total Pasture Production increased by 20, 17, and 15% for urea + Agrotain + S, urea + Agrotain, and urea + DI treatments, respectively, representing 86, 71, and 64% increases in N response efficiency. Total N uptake in urea + Agrotain, urea + Agrotain + S, and urea + DI increased by 29, 22, and 20%, respectively, compared to urea alone. These results suggest that the combination of both urease and nitrification inhibitors may have the most potential to reduce N losses and improve Pasture Production in intensively grazed systems.
J D Blennerhassett - One of the best experts on this subject based on the ideXlab platform.
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effects of the different rates of urease and nitrification inhibitors on gaseous emissions of ammonia and nitrous oxide nitrate leaching and Pasture Production from urine patches in an intensive grazed Pasture system
Agriculture Ecosystems & Environment, 2010Co-Authors: M Zaman, J D BlennerhassettAbstract:Abstract Minimizing nitrogen (N) losses via ammonia (NH 3 ) and nitrous oxide (N 2 O) emissions into the atmosphere and nitrate (NO 3 − ) leaching into surface and ground waters from intensively grazed Pastures is essential for environmental protection worldwide. Applying urease inhibitor such as N-(n-butyl) thiophosphoric triamide (nBPT) or (Agrotain) and nitrification inhibitor dicyandiamide (DCD) to grazed Pastures has the potential to mitigate such N losses. A lysimeter/mini plot experiment, using Paparua silt loam soil near Lincoln, Canterbury New Zealand, was conducted to quantify these N losses during May 2007 to July 2008. The nine treatments were: cow urine only applied at an equivalent rate of 600 kg N ha −1 , urine + DCD at 5 kg ha −1 , urine + DCD at 7 kg ha −1 , urine + DCD at 10 kg ha −1 , urine + double inhibitor (DI), i.e. both Agrotain and DCD applied at 1 L ha −1 and 7 kg ha −1 , respectively (or 1:7 of v/w basis), urine + DI (1:10), urine + DI (2:7), urine + DI (2:10) and the control (no urine). These treatments were randomly applied to one set of lysimeters or mini plots in May as autumn and then to another set of lysimeters or mini plots in August as spring applications. Additional nine lysimeters received DCD only at rates equivalent to 5, 7 and 10 kg ha −1 in autumn to see if DCD has any effect on NO 3 − leaching and Pasture Production and N uptake from non-urine patches in autumn. Gaseous emissions of NH 3 and N 2 O, NO 3 − leaching and Pasture Production and N uptake varied with the types and rates of the applied inhibitors during the two seasons. DCD applied at 7 and 10 kg ha −1 rates with urine was more effective than its lower rate of 5 kg ha −1 and reduced N 2 O emissions by 37–53% (autumn) and 47% (spring), NO 3 − leaching losses by 57–55% (autumn) and 26–10% (spring) compared with urine alone. However DCD increased NH 3 emissions by 41% and 18% compared with urine alone treatment after autumn and spring, respectively. DCD applied at higher rates also increased Pasture dry matter by 9% and 12% and N uptake by 12% and 6% after autumn and spring applications, respectively. However DCD applied at different rates without urine in autumn had no such effect on either NO 3 − leaching or Pasture dry matter yield or N uptake. The DI at 1:7 ratio was more effective than the higher rates of DI and DCD in reducing losses of NH 3 (48% and 51%), N 2 O (55% and 63%) and NO 3 − leaching (56% and 42%) as well as increasing Pasture Production (13% and 17%) and N uptake (7% and 18%) compared with urine alone treatment in autumn and spring, respectively. These results suggest that applying Agrotain + DCD at a ratio of 1:7 (v/w) may provide the best option for both mitigating N losses and improving Pasture Production in intensively grazed systems.
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effect of urease and nitrification inhibitors on n transformation gaseous emissions of ammonia and nitrous oxide Pasture yield and n uptake in grazed Pasture system
Soil Biology & Biochemistry, 2009Co-Authors: M Zaman, J D Blennerhassett, S Saggar, Jatinder SinghAbstract:Abstract Nitrogen (N) losses via nitrate (NO 3 − ) leaching, ammonia (NH 3 ) volatilization and nitrous oxide (N 2 O) emissions from grazed Pastures in New Zealand are one of the major contributors to environmental degradation. The use of N inhibitors (urease and nitrification inhibitors) may have a role in mitigating these N losses. A one-year field experiment was conducted on a permanent dairy-grazed Pasture site at Massey University, Palmerston North, New Zealand to quantify these N losses and to assess the effect of N inhibitors in reducing such losses during May 2005–2006. Cow urine at 600 kg N ha −1 rate with or without urease inhibitor N-(n-butyl) thiophosphoric triamide (nBTPT) or (trade name “Agrotain”) (3 L ha −1 ), nitrification inhibitor dicyandiamide (DCD) (7 kg ha −1 ) and the use of double inhibitor (DI) containing a combination of both Agrotain and DCD (3:7) were applied to field plots in autumn, spring and summer. Pasture Production, NH 3 and N 2 O fluxes, soil mineral N concentrations, microbial biomass C and N, and soil pH were measured following the application of treatments during each season. All measured parameters, except soil microbial biomass C and N, were influenced by the added inhibitors during the three seasons. Agrotain reduced NH 3 emissions over urine alone by 29%, 93% and 31% in autumn, spring and summer respectively but had little effect on N 2 O emission. DCD reduced N 2 O emission over urine alone by 52%, 39% and 16% in autumn, spring and summer respectively but increased NH 3 emission by 56%, 9% and 17% over urine alone during those three seasons. The double inhibitor reduced NH 3 by 14%, 78% and 9% and N 2 O emissions by 37%, 67% and 28% over urine alone in autumn, spring and summer respectively. The double inhibitor also increased Pasture dry matter by 10%, 11% and 8% and N uptake by the 17%, 28% and 10% over urine alone during autumn, spring and summer respectively. Changes in soil mineral N and pH suggested a delay in urine-N hydrolysis with Agrotain, and reduced nitrification with DCD. The combination of Agrotain and DCD was more effective in reducing both NH 3 and N 2 O emissions, improving Pasture Production, controlling urea hydrolysis and retaining N in NH 4 + form. These results suggest that the combination of both urease and nitrification inhibitors may have the most potential to reduce N losses if losses are associated with urine and improve Pasture Production in intensively grazed systems.
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reducing nh3 n2o and text no _3 n losses from a Pasture soil with urease or nitrification inhibitors and elemental s amended nitrogenous fertilizers
Biology and Fertility of Soils, 2008Co-Authors: M Zaman, M L Nguyen, J D Blennerhassett, B F QuinAbstract:A 3-month field experiment comparing nitrogen (N) losses from and the agronomic efficiency of various N fertilizers was conducted on a sandy loam (Typic Hapludand) soil at Ruakura AgResearch farm, Hamilton, New Zealand during October to December 2003. Three replicates of seven treatments: urea, urea + the urease inhibitor N-(n-butyl) thiophosphoric triamide (trade name Agrotain), urea + Agrotain + elemental sulphur (S), urea + double inhibitor [DI; i.e., Agrotain + dicyandiamide (DCD)], diammonium phosphate (DAP), DAP + S, each applied at 150 kg N ha−1, and control (no N). After fertilizer application, soil ammonium (\( \operatorname{NH} ^{ + }_{4} \)) and nitrate (\( \operatorname{NO} ^{ - }_{3} \)) concentrations (7.5-cm soil depth), ammonia (NH3) volatilization, nitrate (\( \operatorname{NO} ^{ - }_{3} \)) leaching, nitrous oxide (N2O) emission, Pasture dry matter, and N uptake were monitored at different timings. Urea applied with Agrotain or Agrotain + S delayed urea hydrolysis and released soil \( \operatorname{NH} ^{ + }_{4} \) at a slower rate than urea alone or urea + DI. Urea applied with DI increased NH3 volatilization by 29% over urea alone, while urea + Agrotain and urea + Agrotain + S reduced NH3 volatilization by 45 and 48%, respectively. Ammonia volatilization losses from DAP were lower than those from urea with or without inhibitors. Total reduction in \( \operatorname{NO} ^{ - }_{3} \) leaching losses for urea + DI and urea + Agrotain compared to urea alone were 89% and 47%, respectively. Application of S with urea + Agrotain reduced \( \operatorname{NO} ^{ - }_{3} \) leaching losses by an additional 6%. Nitrous oxide emissions were higher from the DAP and urea alone treatments. Urea applied with DI and urea + Agrotain reduced N2O emissions by 37 and 5%, respectively, over urea alone. Compared to urea alone, total Pasture Production increased by 20, 17, and 15% for urea + Agrotain + S, urea + Agrotain, and urea + DI treatments, respectively, representing 86, 71, and 64% increases in N response efficiency. Total N uptake in urea + Agrotain, urea + Agrotain + S, and urea + DI increased by 29, 22, and 20%, respectively, compared to urea alone. These results suggest that the combination of both urease and nitrification inhibitors may have the most potential to reduce N losses and improve Pasture Production in intensively grazed systems.
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reducing nh 3 n 2 o and text no _3 n losses from a Pasture soil with urease or nitrification inhibitors and elemental s amended nitrogenous fertilizers
Biology and Fertility of Soils, 2008Co-Authors: M Zaman, M L Nguyen, J D Blennerhassett, B F QuinAbstract:A 3-month field experiment comparing nitrogen (N) losses from and the agronomic efficiency of various N fertilizers was conducted on a sandy loam (Typic Hapludand) soil at Ruakura AgResearch farm, Hamilton, New Zealand during October to December 2003. Three replicates of seven treatments: urea, urea + the urease inhibitor N-(n-butyl) thiophosphoric triamide (trade name Agrotain), urea + Agrotain + elemental sulphur (S), urea + double inhibitor [DI; i.e., Agrotain + dicyandiamide (DCD)], diammonium phosphate (DAP), DAP + S, each applied at 150 kg N ha−1, and control (no N). After fertilizer application, soil ammonium ( $$ \operatorname{NH} ^{ + }_{4} $$ ) and nitrate ( $$ \operatorname{NO} ^{ - }_{3} $$ ) concentrations (7.5-cm soil depth), ammonia (NH3) volatilization, nitrate ( $$ \operatorname{NO} ^{ - }_{3} $$ ) leaching, nitrous oxide (N2O) emission, Pasture dry matter, and N uptake were monitored at different timings. Urea applied with Agrotain or Agrotain + S delayed urea hydrolysis and released soil $$ \operatorname{NH} ^{ + }_{4} $$ at a slower rate than urea alone or urea + DI. Urea applied with DI increased NH3 volatilization by 29% over urea alone, while urea + Agrotain and urea + Agrotain + S reduced NH3 volatilization by 45 and 48%, respectively. Ammonia volatilization losses from DAP were lower than those from urea with or without inhibitors. Total reduction in $$ \operatorname{NO} ^{ - }_{3} $$ leaching losses for urea + DI and urea + Agrotain compared to urea alone were 89% and 47%, respectively. Application of S with urea + Agrotain reduced $$ \operatorname{NO} ^{ - }_{3} $$ leaching losses by an additional 6%. Nitrous oxide emissions were higher from the DAP and urea alone treatments. Urea applied with DI and urea + Agrotain reduced N2O emissions by 37 and 5%, respectively, over urea alone. Compared to urea alone, total Pasture Production increased by 20, 17, and 15% for urea + Agrotain + S, urea + Agrotain, and urea + DI treatments, respectively, representing 86, 71, and 64% increases in N response efficiency. Total N uptake in urea + Agrotain, urea + Agrotain + S, and urea + DI increased by 29, 22, and 20%, respectively, compared to urea alone. These results suggest that the combination of both urease and nitrification inhibitors may have the most potential to reduce N losses and improve Pasture Production in intensively grazed systems.
B F Quin - One of the best experts on this subject based on the ideXlab platform.
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reducing nh3 n2o and text no _3 n losses from a Pasture soil with urease or nitrification inhibitors and elemental s amended nitrogenous fertilizers
Biology and Fertility of Soils, 2008Co-Authors: M Zaman, M L Nguyen, J D Blennerhassett, B F QuinAbstract:A 3-month field experiment comparing nitrogen (N) losses from and the agronomic efficiency of various N fertilizers was conducted on a sandy loam (Typic Hapludand) soil at Ruakura AgResearch farm, Hamilton, New Zealand during October to December 2003. Three replicates of seven treatments: urea, urea + the urease inhibitor N-(n-butyl) thiophosphoric triamide (trade name Agrotain), urea + Agrotain + elemental sulphur (S), urea + double inhibitor [DI; i.e., Agrotain + dicyandiamide (DCD)], diammonium phosphate (DAP), DAP + S, each applied at 150 kg N ha−1, and control (no N). After fertilizer application, soil ammonium (\( \operatorname{NH} ^{ + }_{4} \)) and nitrate (\( \operatorname{NO} ^{ - }_{3} \)) concentrations (7.5-cm soil depth), ammonia (NH3) volatilization, nitrate (\( \operatorname{NO} ^{ - }_{3} \)) leaching, nitrous oxide (N2O) emission, Pasture dry matter, and N uptake were monitored at different timings. Urea applied with Agrotain or Agrotain + S delayed urea hydrolysis and released soil \( \operatorname{NH} ^{ + }_{4} \) at a slower rate than urea alone or urea + DI. Urea applied with DI increased NH3 volatilization by 29% over urea alone, while urea + Agrotain and urea + Agrotain + S reduced NH3 volatilization by 45 and 48%, respectively. Ammonia volatilization losses from DAP were lower than those from urea with or without inhibitors. Total reduction in \( \operatorname{NO} ^{ - }_{3} \) leaching losses for urea + DI and urea + Agrotain compared to urea alone were 89% and 47%, respectively. Application of S with urea + Agrotain reduced \( \operatorname{NO} ^{ - }_{3} \) leaching losses by an additional 6%. Nitrous oxide emissions were higher from the DAP and urea alone treatments. Urea applied with DI and urea + Agrotain reduced N2O emissions by 37 and 5%, respectively, over urea alone. Compared to urea alone, total Pasture Production increased by 20, 17, and 15% for urea + Agrotain + S, urea + Agrotain, and urea + DI treatments, respectively, representing 86, 71, and 64% increases in N response efficiency. Total N uptake in urea + Agrotain, urea + Agrotain + S, and urea + DI increased by 29, 22, and 20%, respectively, compared to urea alone. These results suggest that the combination of both urease and nitrification inhibitors may have the most potential to reduce N losses and improve Pasture Production in intensively grazed systems.
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reducing nh 3 n 2 o and text no _3 n losses from a Pasture soil with urease or nitrification inhibitors and elemental s amended nitrogenous fertilizers
Biology and Fertility of Soils, 2008Co-Authors: M Zaman, M L Nguyen, J D Blennerhassett, B F QuinAbstract:A 3-month field experiment comparing nitrogen (N) losses from and the agronomic efficiency of various N fertilizers was conducted on a sandy loam (Typic Hapludand) soil at Ruakura AgResearch farm, Hamilton, New Zealand during October to December 2003. Three replicates of seven treatments: urea, urea + the urease inhibitor N-(n-butyl) thiophosphoric triamide (trade name Agrotain), urea + Agrotain + elemental sulphur (S), urea + double inhibitor [DI; i.e., Agrotain + dicyandiamide (DCD)], diammonium phosphate (DAP), DAP + S, each applied at 150 kg N ha−1, and control (no N). After fertilizer application, soil ammonium ( $$ \operatorname{NH} ^{ + }_{4} $$ ) and nitrate ( $$ \operatorname{NO} ^{ - }_{3} $$ ) concentrations (7.5-cm soil depth), ammonia (NH3) volatilization, nitrate ( $$ \operatorname{NO} ^{ - }_{3} $$ ) leaching, nitrous oxide (N2O) emission, Pasture dry matter, and N uptake were monitored at different timings. Urea applied with Agrotain or Agrotain + S delayed urea hydrolysis and released soil $$ \operatorname{NH} ^{ + }_{4} $$ at a slower rate than urea alone or urea + DI. Urea applied with DI increased NH3 volatilization by 29% over urea alone, while urea + Agrotain and urea + Agrotain + S reduced NH3 volatilization by 45 and 48%, respectively. Ammonia volatilization losses from DAP were lower than those from urea with or without inhibitors. Total reduction in $$ \operatorname{NO} ^{ - }_{3} $$ leaching losses for urea + DI and urea + Agrotain compared to urea alone were 89% and 47%, respectively. Application of S with urea + Agrotain reduced $$ \operatorname{NO} ^{ - }_{3} $$ leaching losses by an additional 6%. Nitrous oxide emissions were higher from the DAP and urea alone treatments. Urea applied with DI and urea + Agrotain reduced N2O emissions by 37 and 5%, respectively, over urea alone. Compared to urea alone, total Pasture Production increased by 20, 17, and 15% for urea + Agrotain + S, urea + Agrotain, and urea + DI treatments, respectively, representing 86, 71, and 64% increases in N response efficiency. Total N uptake in urea + Agrotain, urea + Agrotain + S, and urea + DI increased by 29, 22, and 20%, respectively, compared to urea alone. These results suggest that the combination of both urease and nitrification inhibitors may have the most potential to reduce N losses and improve Pasture Production in intensively grazed systems.
J R Roche - One of the best experts on this subject based on the ideXlab platform.
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short communication effect of stocking rate on the economics of Pasture based dairy farms
Journal of Dairy Science, 2011Co-Authors: K A Macdonald, J W Penno, J A S Lancaster, D Beca, J R RocheAbstract:Data from a multiyear farm systems study evaluating the effect of stocking rate (SR) on Pasture Production and utilization, milk Production per cow and per hectare, reProduction, and cow health were used to determine the economic implications of altering SR. The effect of SR was also evaluated relative to cow size and total feed available (comparative stocking rate; CSR), to account for differences in cow size and feed supplement availability. Milk Production, gross revenue, operating expenses, and operating profit per cow all declined with increasing SR and CSR. In comparison, milk Production, gross revenue, and operating expenses per hectare increased with increasing SR and CSR. These effects were irrespective of milk price. The effect of SR on operating profit and return on assets, however, was dependent on milk payment system. When payment was based on the economic value of milk fat and protein, operating profit and return on assets were quadratically associated with both SR and CSR, declining at an SR greater or less than 3.3 cows/ha and a CSR greater or less than 77 kg of body weight/t of feed dry matter available. In comparison, when milk payment was based on a fluid milk pricing system, profit per hectare increased linearly with increasing SR and CSR, but return on assets was not affected by SR or CSR.
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effect of stocking rate on Pasture Production milk Production and reProduction of dairy cows in Pasture based systems
Journal of Dairy Science, 2008Co-Authors: K A Macdonald, J W Penno, J A S Lancaster, J R RocheAbstract:Ninety-four cows were randomly allocated to 1 of 5 stocking rates (2.2, 2.7, 3.1, 3.7, and 4.3 cows/ha) in a completely randomized design for 3 years. Herds were seasonal calving, with only minor differences in grazing management to optimize the profitability of each stocking rate (SR). Pasture Production and quality data, milk and milk component data, and reProduction data were collected, averaged for SR treatment, and linear and quadratic contrasts on SR were evaluated. In addition, the Wilmink exponential model (y(t) = a + b x e((-0.05t) )+ c x t) was fitted to milk yield within lactation, and the parameters were averaged by SR treatment and analyzed as above. The median variation explained by the function for individual lactations was 84%. The amount of Pasture grown tended to increase, and the quality of the Pasture on offer increased linearly with increasing SR, reducing some of the negative impact of SR on the availability of Pasture per cow. Milk Production per cow declined linearly with increasing SR, although there was a tendency for most Production variables to decline quadratically, with the negative effect of SR declining with increasing SR. The effect on milk Production per cow was primarily because of a lower peak milk yield and a greater post-peak decline (less persistent milk profile), although a decline in lactation length with increasing SR was responsible for 24% of the effect of SR on milk yield. Milk Production per hectare increased linearly with increasing SR, and there was only a small difference (approximately 3%/cow per ha) in the efficiency of converting feed dry matter into milk energy. Stocking rate did not affect reproductive success. The data are consistent with the need for a more robust measure of SR than cows per hectare because farms will differ in the genetic merit of their cows and in the potential to produce Pasture. We introduce the concept of a comparative SR, whereby the carrying capacity of the farm is defined by the BW of the cows, the potential of the land to produce Pasture, and the amount of supplement purchased (kg of BW/t of feed dry matter). The adoption of such a measure would facilitate the extrapolation and transfer of research findings among systems.
R J Paton - One of the best experts on this subject based on the ideXlab platform.
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land use intensification in new zealand effects on soil properties and Pasture Production
The Journal of Agricultural Science, 2011Co-Authors: D J Houlbrooke, R J Paton, R P Littlejohn, J D MortonAbstract:Land-use intensification requires more farm inputs to sustain or increase farm product outputs. However, a common concern for land-use intensification is the potential deterioration of soil. The North Otago Rolling Downlands (NORD) region of New Zealand is drought prone, and although traditionally limited to extensive sheep farming, there are large-scale conversions to intensive cattle grazing operations such as dairy farming resulting from an irrigation scheme commissioned in 2006. Pallic soils (Aeric Fragiaqualf in US Soil Taxonomy) such as those in the NORD region are prone to soil compaction because of their ‘high’ structural vulnerability under intensive management. To address these concerns, a field trial was established on a common NORD Pallic soil (Timaru silt loam) to determine how land-use intensification affects indicators of soil quality (macroporosity, bulk density, structural condition score, total and mineralizable carbon and nitrogen and earthworms) and Pasture Production. The treatments compare irrigated v . dryland Pasture and sheep v . cattle grazing on 16 plots. The findings show that soil physical quality responds more quickly to changes in land-use pressure than do biochemical and organic indicators. Both irrigation and cattle grazing, particularly in combination, increased soil compaction; macroporosity on irrigated plots grazed by cattle ranged from 9·1 to 13·3% v/v at a depth of 0–50 mm, compared to dryland plots with sheep grazing (18·9–23·0% v/v). Soil compaction/damage has implications for Pasture Production, soil hydrology and nutrient movement. Land management practices for intensive cattle grazing of irrigated soil prone to treading damage therefore need to implement high compaction risk strategies to avoid or ameliorate potential changes to soil quality.
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grazing strategies to protect soil physical properties and maximise Pasture yield on a southland dairy farm
New Zealand Journal of Agricultural Research, 2009Co-Authors: D J Houlbrooke, J J Drewry, R J Paton, R M Monaghan, L C Smith, R P LittlejohnAbstract:Abstract intensive dairy cattle grazing on wet soil can have a detrimental effect on soil physical quality and consequently on Pasture Production. Soil physical properties (porosity, bulk density, saturated hydraulic conductivity) of a Pallic soil (Pukemutu silt loam) and Pasture Production were assessed on a dairy farm in Southland, New Zealand, under a number of different cattle grazing strategies: (i) normal grazing management on undrained land, (ii) normal grazing practice on drained land, (iii) restricted autumn grazing, (iv) restricted grazing when soil conditions were wet, (v) never pugged, and (vi) never grazed. a hand‐pushed cone penetrometer determined treatments (iv) and (v). Soil macroporos‐ity was significantly greater (P < 0.05) on the never grazed plot than all other treatments at post‐spring sampling each year. There were no significant differences in any soil physical properties measured on cattle grazed treatments. Spring Pasture yield from the never grazed treatment was greater (P < 0.0...
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effect of subsoiling on soil physical properties and dry matter Production on a brown soil in southland new zealand
New Zealand Journal of Agricultural Research, 2000Co-Authors: J J Drewry, R J PatonAbstract:Abstract This study examined the effect of shallow subsoiling on soil physical properties and ryegrass‐white clover Pasture Production on a Waikiwi silt loam (Brown Soil) over 2.5 years. Macroporosity, hydraulic conductivity, and air permeability were measured in 6‐cm increments down to 30 cm soil depth. The topsoil was loosened by pulling both conventional tines or wing‐shaped tines set at 50 cm apart through the soil, at a depth of 25–30 cm. Subsoiling increased macroporosity by up to 39% of the soil volume, and increased saturated hydraulic conductivity and air permeability by up to two orders of magnitude. Improvements in soil physical conditions were evident for up to 2 years after subsoiling with both the winged tines and conventional tines, although there were few differences between the tine types. Some recompaction and settling over time occurred in the upper 12 cm of the soil profile. For the second year, the conventional tine subsoiling treatment reduced total Production by 9%. Pasture dry matt...
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effect of subsoiling on soil physical properties and Pasture Production on a pallic soil in southland new zealand
New Zealand Journal of Agricultural Research, 2000Co-Authors: J J Drewry, J A H Lowe, R J PatonAbstract:Abstract This three‐year study examined the effects on soil physical properties and ryegrass‐white clover Pasture Production of subsoiling in a Pukemutu silt loam (Pallic Soil). A range of soil physical properties were measured in 6‐cm incremental depths to 30 cm. Subsoiling loosened the topsoil by pulling conventional tines and winged tines, 50 cm apart through the soil at a depth of 25–30 cm. Subsoiling increased macroporosity by up to 27% of the soil volume, and increased saturated hydraulic conductivity and air permeability by up to two orders of magnitude. Improvements in soil physical conditions were evident up to 2.5 years after subsoiling at 18–24 cm, although recompaction and settling had occurred in the upper 18 cm of the soil profile. For the majority of the trial, there was no significant improvement in Pasture Production in subsoiled treatments. Pasture dry matter was significantly reduced (by 39%) during a dry summer period following winged subsoiling, mainly due to moisture stress.
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effect of sheep stocking intensity on soil physical properties and dry matter Production on a pallid soil in southland
New Zealand Journal of Agricultural Research, 1999Co-Authors: J J Drewry, J A H Lowe, R J PatonAbstract:Abstract This 3‐year study examined the extent of damage to soil physical properties of a Pukemutu silt loam (Pallic Soil) and the loss of ryegrass‐white clover Pasture Production caused by intensive winter grazing at 1800 sheep ha−1. Macroporosity, pore size distribution, bulk density, and hydraulic conductivity were measured at 5‐cm incremental soil depths to 15 cm to assess changes in soil compaction. Soil smearing on intensively winter‐grazed plots suggested that soil structural damage had occurred. Soil physical tests, three weeks after winter grazing, in August 1994 and 1995, however, showed only slight compaction at the surface. Macroporosity in the 0–5 cm soil depth was significantly reduced from 16.4% to 12.1% by the intensive winter grazing treatment. Soil pores were water‐filled leading to plastic deformation rather than compaction. Spring Pasture Production was also significantly decreased (21%) following the 1994 winter grazing, but growth recovered the following summer. Macroporosity was gen...