title: Effects of prolonged oral administration of dicyandiamide to dairy heifers on excretion in urine and efficacy in soil

authors: Welten, Brendon Grant

subjects: nitrification inhibitor

abstract: Oral administration of the nitrification inhibitor dicyandiamide (DCD) to grazing ruminants for excretion in urine represents a targeted mitigation strategy to reduce nitrogen (N) losses from grazed pastures. A field trial and allied laboratory incubation study were conducted to examine the effects of oral administration of DCD to non-lactating Friesian dairy heifers on excretion of DCD in urine and efficacy in soil. Dairy heifers were orally administered DCD daily at three treatment levels (low, medium and high; 12, 24 and 36 g DCD heiferˉ¹ day ˉ¹, respectively) and compared to a nil-DCD control group over a 90-day continuous dosing period. There were no adverse effects of DCD administration on heifer health or growth, as inferred by live-weight gain and measured blood metabolite levels. Prolonged administration of DCD to dairy heifers resulted in the sustained excretion of DCD in the urine over 90 days and inhibition of nitrification of urinary-N in the silty peat soil for up to 56 days (incubated at 20 °C; P < 0.001). Field soil sampling (0–75 mm depth) of individual urine patches for DCD analysis revealed that a 3-fold increase in the rate of DCD administered resulted in a similar increase in the concentration of DCD voided in the urine and subsequently deposited in urine patches (median equivalent DCD application rates of 22, 36 and 59 kg ha ˉ¹ for the low, medium and high DCD treatment levels, respectively; P < 0.001). However, large differences (up to 40-fold) existed between individual urine patches in the rate of DCD deposited at each treatment level, which showed a positively skewed distribution. This study highlights the viability of prolonged daily administration of DCD to ruminants for sustained excretion in urine and effective inhibition of nitrification in soil as a practical targeted mitigation technology to reduce urinary-N losses from grazed pastures.

text: Effects of prolonged oral administration of dicyandiamide to dairy heifers on excretion in urine and efficacy in soil Oral administration of the nitrification inhibitor dicyandiamide (DCD) to grazing ruminants for excretion in urine represents a targeted mitigation strategy to reduce nitrogen (N) losses from grazed pastures. A field trial and allied laboratory incubation study were conducted to examine the effects of oral administration of DCD to non-lactating Friesian dairy heifers on excretion of DCD in urine and efficacy in soil. Dairy heifers were orally administered DCD daily at three treatment levels (low, medium and high; 12, 24 and 36 g DCD heiferˉ¹ day ˉ¹, respectively) and compared to a nil-DCD control group over a 90-day continuous dosing period. There were no adverse effects of DCD administration on heifer health or growth, as inferred by live-weight gain and measured blood metabolite levels. Prolonged administration of DCD to dairy heifers resulted in the sustained excretion of DCD in the urine over 90 days and inhibition of nitrification of urinary-N in the silty peat soil for up to 56 days (incubated at 20 °C; P < 0.001). Field soil sampling (0–75 mm depth) of individual urine patches for DCD analysis revealed that a 3-fold increase in the rate of DCD administered resulted in a similar increase in the concentration of DCD voided in the urine and subsequently deposited in urine patches (median equivalent DCD application rates of 22, 36 and 59 kg ha ˉ¹ for the low, medium and high DCD treatment levels, respectively; P < 0.001). However, large differences (up to 40-fold) existed between individual urine patches in the rate of DCD deposited at each treatment level, which showed a positively skewed distribution. This study highlights the viability of prolonged daily administration of DCD to ruminants for sustained excretion in urine and effective inhibition of nitrification in soil as a practical targeted mitigation technology to reduce urinary-N losses from grazed pastures.

year: 2013

title: Book cover 'David Bowie and the Art of Music Video'

authors: Perrott, Lisa

subjects: Art

abstract: The book cover for 'David Bowie and the Art of Music Video' was designed and painted by Lisa Perrott, who is the copyright holder for this cover image. Lisa Perrott painted this image using water colours on paper, then photographed the painting and designed the cover design using photoshop.

text: Book cover 'David Bowie and the Art of Music Video' The book cover for 'David Bowie and the Art of Music Video' was designed and painted by Lisa Perrott, who is the copyright holder for this cover image. Lisa Perrott painted this image using water colours on paper, then photographed the painting and designed the cover design using photoshop.

year: 2023-07-27

title: Te Whariki revisited: How approaches to assessment can make valued learning visible

authors: McLachlan, Claire

abstract: In 2016, Te Whariki: He Whariki Matauranga mō ngā Mokopuna o Aotearoa: Early Childhood Curriculum (Te Whariki) (Ministry of Education [MoE], 2017), New Zealand’s early childhood curriculum was updated for the first time in 20 years. Although the gazetted principles, strands and goals of the curriculum were not part of the update, the remainder of the curriculum was revised to meet the changing social and linguistic context, the revised national curriculum and associated documents, reviews of early childhood practice and relevant theory and research. The updated curriculum has reduced learning outcomes (from 118 to 20) and stronger guidance on the need for both informal and formal approaches to assessment to ensure children’s learning in each strand are assessed. This article reflects on the changes between the 1996 and 2017 version of the curriculum in relation to assessment and the rationale for the changes. Approaches to both ‘in the moment’ and planned assessment are explored and the usefulness of approaches which enable teachers to reflect on ‘discrepant data’ and support children’s learning in each strand are examined.

text: Te Whariki revisited: How approaches to assessment can make valued learning visible In 2016, Te Whariki: He Whariki Matauranga mō ngā Mokopuna o Aotearoa: Early Childhood Curriculum (Te Whariki) (Ministry of Education [MoE], 2017), New Zealand’s early childhood curriculum was updated for the first time in 20 years. Although the gazetted principles, strands and goals of the curriculum were not part of the update, the remainder of the curriculum was revised to meet the changing social and linguistic context, the revised national curriculum and associated documents, reviews of early childhood practice and relevant theory and research. The updated curriculum has reduced learning outcomes (from 118 to 20) and stronger guidance on the need for both informal and formal approaches to assessment to ensure children’s learning in each strand are assessed. This article reflects on the changes between the 1996 and 2017 version of the curriculum in relation to assessment and the rationale for the changes. Approaches to both ‘in the moment’ and planned assessment are explored and the usefulness of approaches which enable teachers to reflect on ‘discrepant data’ and support children’s learning in each strand are examined.

year: 2018