s Two plant growth regulator (PGR) products currently available in New Zealand and a new Ravensdo... more s Two plant growth regulator (PGR) products currently available in New Zealand and a new Ravensdown PGR product-Express TM* , all based on gibberellic acid (GA3), were applied to a Canterbury dairy pasture in late winter (August) and early spring (September) and their effect on dry-matter (DM) yield was measured. PGR treatments were compared with both an application of liquid urea (20 kg N/ha) alone and a urea plus Express treatment. In the first harvest of both winterand spring-initiated trials, a month following PGR application, the PGR treatments produced significant increases in DM yield ranging from 1851% over the control. These increases, however, did not extend to the second harvest in either trial for any of the PGR agents. The application of urea increased production in the 1 st harvest by ~36% in both trials but this was increased to over 60% when combined with Express TM . No effect of the PGR was apparent in the second harvest where the urea treatment alone was the highe...
Two plant growth regulator (PGR) products currently available in New Zealand and a new Ravensdown... more Two plant growth regulator (PGR) products currently available in New Zealand and a new Ravensdown PGR product-Express TM* , all based on gibberellic acid (GA 3), were applied to a Canterbury dairy pasture in late winter (August) and early spring (September) and their effect on dry-matter (DM) yield was measured. PGR treatments were compared with both an application of liquid urea (20 kg N/ha) alone and a urea plus Express treatment. In the first harvest of both winter-and spring-initiated trials, a month following PGR application, the PGR treatments produced significant increases in DM yield ranging from 18-51% over the control. These increases, however, did not extend to the second harvest in either trial for any of the PGR agents. The application of urea increased production in the 1 st harvest by ~36% in both trials but this was increased to over 60% when combined with Express TM. No effect of the PGR was apparent in the second harvest where the urea treatment alone was the highest DM producer. These trials showed some benefit in the use of PGR products when there is a need to boost pasture growth in early spring but these benefits largely disappeared after the first month following application. Some future research may be useful to further optimise parameters for the use of PGR products. * Express TM is a trademark of Ravensdown Fertiliser cooperative Ltd. It is registered pursuant to the ACVM Act 1991997, No.8341.
This experiment investigated bacterial transport from land-applied dairy shed effluent (DSE), via... more This experiment investigated bacterial transport from land-applied dairy shed effluent (DSE), via field lysimeter studies, using 2 contrasting irrigation methods. Transient water flow and bacterial transport were studied, and the factors controlling faecal coliform (FC) transport are discussed. Two trials (Trial 1, summer; Trial 2, autumn) were carried out, using 6 undisturbed soil monolith lysimeters, 500 mm diameter by 700 mm deep, with a free-draining, Templeton fine sandy loam. DSE with inert chemical tracers was applied at the start of both trials using the same method, followed with repeated 14-day cycles of either flood or spray irrigation of water. A bacterial tracer, antibiotic-resistant faecal coliform, was added to the DSE in Trial 2 only, to distinguish applied FC from external or resident FC. Leachates were collected after each water application (or heavy rainfall when applicable) for enumeration of FC and measurement of tracers. All lysimeters were instrumented for mon...
HYDRUS-1D was used to simulate water flow and leaching of fecal coliforms and bromide (Br) throug... more HYDRUS-1D was used to simulate water flow and leaching of fecal coliforms and bromide (Br) through six undisturbed soil lysimeters (70cm depth by 50cm diameter) under field conditions. Dairy shed effluent (DSE) spiked with Br was applied to the lysimeters, which ...
s Two plant growth regulator (PGR) products currently available in New Zealand and a new Ravensdo... more s Two plant growth regulator (PGR) products currently available in New Zealand and a new Ravensdown PGR product-Express TM* , all based on gibberellic acid (GA3), were applied to a Canterbury dairy pasture in late winter (August) and early spring (September) and their effect on dry-matter (DM) yield was measured. PGR treatments were compared with both an application of liquid urea (20 kg N/ha) alone and a urea plus Express treatment. In the first harvest of both winterand spring-initiated trials, a month following PGR application, the PGR treatments produced significant increases in DM yield ranging from 1851% over the control. These increases, however, did not extend to the second harvest in either trial for any of the PGR agents. The application of urea increased production in the 1 st harvest by ~36% in both trials but this was increased to over 60% when combined with Express TM . No effect of the PGR was apparent in the second harvest where the urea treatment alone was the highe...
Two plant growth regulator (PGR) products currently available in New Zealand and a new Ravensdown... more Two plant growth regulator (PGR) products currently available in New Zealand and a new Ravensdown PGR product-Express TM* , all based on gibberellic acid (GA 3), were applied to a Canterbury dairy pasture in late winter (August) and early spring (September) and their effect on dry-matter (DM) yield was measured. PGR treatments were compared with both an application of liquid urea (20 kg N/ha) alone and a urea plus Express treatment. In the first harvest of both winter-and spring-initiated trials, a month following PGR application, the PGR treatments produced significant increases in DM yield ranging from 18-51% over the control. These increases, however, did not extend to the second harvest in either trial for any of the PGR agents. The application of urea increased production in the 1 st harvest by ~36% in both trials but this was increased to over 60% when combined with Express TM. No effect of the PGR was apparent in the second harvest where the urea treatment alone was the highest DM producer. These trials showed some benefit in the use of PGR products when there is a need to boost pasture growth in early spring but these benefits largely disappeared after the first month following application. Some future research may be useful to further optimise parameters for the use of PGR products. * Express TM is a trademark of Ravensdown Fertiliser cooperative Ltd. It is registered pursuant to the ACVM Act 1991997, No.8341.
This experiment investigated bacterial transport from land-applied dairy shed effluent (DSE), via... more This experiment investigated bacterial transport from land-applied dairy shed effluent (DSE), via field lysimeter studies, using 2 contrasting irrigation methods. Transient water flow and bacterial transport were studied, and the factors controlling faecal coliform (FC) transport are discussed. Two trials (Trial 1, summer; Trial 2, autumn) were carried out, using 6 undisturbed soil monolith lysimeters, 500 mm diameter by 700 mm deep, with a free-draining, Templeton fine sandy loam. DSE with inert chemical tracers was applied at the start of both trials using the same method, followed with repeated 14-day cycles of either flood or spray irrigation of water. A bacterial tracer, antibiotic-resistant faecal coliform, was added to the DSE in Trial 2 only, to distinguish applied FC from external or resident FC. Leachates were collected after each water application (or heavy rainfall when applicable) for enumeration of FC and measurement of tracers. All lysimeters were instrumented for mon...
HYDRUS-1D was used to simulate water flow and leaching of fecal coliforms and bromide (Br) throug... more HYDRUS-1D was used to simulate water flow and leaching of fecal coliforms and bromide (Br) through six undisturbed soil lysimeters (70cm depth by 50cm diameter) under field conditions. Dairy shed effluent (DSE) spiked with Br was applied to the lysimeters, which ...
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