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• A kānuka silvopastoral system had greater surface runoff compared to open pasture. • Sediment and nutrient loads were 10 to 100 times greater under the trees. • Sediment and nutrient loads were a function of increasing surface runoff. • Vegetation was grazed lower under the trees, reducing surface runoff attenuation. • Surface runoff was greater under kānuka despite improved soil conditions. New Zealand hill country is a pastoral region that has high levels of surface runoff and sediment and nutrient losses. Silvopastoralism has potential to mitigate these losses via the interaction of trees with the soil, pasture and livestock. This study compares surface runoff and sediment and nutrient losses (nitrogen and phosphorus) in pasture plots with and without Kunzea robusta (kānuka) trees and investigates the reasons for the variation in these losses between kānuka pasture and open pasture. Annual surface runoff was 54.0 mm in kānuka pasture and 7.6 mm in open pasture despite kānuka pasture having improved soil conditions (in terms of porosity, organic matter and soil fertility). Kānuka pasture had species indicative of good pasture condition even though the plots had significantly less standing grass biomass. This was most likely due to livestock preferentially grazing the pasture under kānuka which led to less attenuation of surface runoff. Sediment and nutrient losses were 10–100 times greater in kānuka pasture, mainly due to the increase in surface runoff, but also because of livestock concentrating nutrients under the trees through excreta deposition. These results are contrary to past silvopastoral research and highlights that an extreme choice between shaded areas of good pasture condition and unshaded areas of poor pasture condition within a pastoral hillside can lead to negative consequences in terms of surface runoff and contaminant losses because of livestock interactions. More research is required to understand these processes in other hill country farms and grazing conditions, and explore mitigation options. [ABSTRACT FROM AUTHOR]

'Tree-pasture' silvopastoral systems have the potential to become transformative multifunctional landscapes that add both environmental and economic value to pastoral farms. Nevertheless, no published study has found increased pasture production under mature silvopastoral trees in New Zealand hill country. This study takes a novel approach to silvopastoral research in New Zealand, and investigates a genus that has similar bio-physical attributes to other global silvopastoral trees that have been shown to increase pasture production under their canopies, with the aim of finding a silvopastoral genera that can increase pasture production under tree canopies compared to open pasture in New Zealand. This study measures pasture and soil variables in two pasture positions: under individually spaced native kānuka (Kunzea spp.) trees (kānuka pasture) and paired open pasture positions at least 15 m from tree trunks (open pasture) at two sites over two years. There was 107.9% more pasture production in kānuka pasture positions. The soil variables that were significantly greater in kānuka pasture were Olsen-P (+115.7%, p < 0.001), K (+100%, p < 0.001), Mg (+33.33%, p < 0.01), Na (+200%, p < 0.001) and porosity (+8.8%, p < 0.05), and Olsen-P, porosity and K best explained the variation between kānuka pasture and open pasture positions. Volumetric soil moisture was statistically similar in kānuka pasture and open pasture positions. These results are evidence of nutrient transfer by livestock to the tree-pasture environment. Furthermore, as there was a significantly greater porosity and 48.6% more organic matter under the trees, there were likely other processes also contributing to the difference between tree and open pasture environments, such as litterfall. These results show that kānuka has potential to increase pasture production in New Zealand hill country farms and create multifunctional landscapes enhancing both production and environmental outcomes in pastoral farms. [ABSTRACT FROM AUTHOR]

Silvopastoral systems have complex impacts on a diverse range of outcomes, making it essential to design these systems using an integrative approach to maximise positive impacts to farms. This paper comprises firstly a systematic review of global silvopastoral processes, and secondly stakeholder-driven synthesis of key opportunities and challenges for future silvopastoralism situated in the context of New Zealand. The systematic review demonstrated that although under-researched, livestock interactions can have overriding influences on the system, and that the traditional functional traits that are typically deemed important for selection (N2-fixing trees v non N2-fixing trees, evergreen v deciduous) do not show consistent positive impacts on the agroecological environment. From the New Zealand silvopastoral participatory case study, including the stakeholder workshop, we synthesised 5 key principles that should be considered in future system designs. These were: (1) silvopastoral systems are complex and require holistic management; (2) the views, values and experiences of local people are deeply connected to silvopastoral system design; (3) spatial heterogeneity in environmental and social conditions requires locally specific decisions; (4) understanding of ecological processes must underpin all management decisions; and (5) the complexity and spatial heterogeneity present in silvopastoral systems requires high-resolution data and tools. [ABSTRACT FROM AUTHOR]

Forage management underpins the viability of pastoral dairy systems. This review investigated recent developments in forage research and their potential to enable pastoral dairy systems to meet the challenges that will be faced over the next 10 years. Grazing management, complementary forages, pasture diversity, fertiliser use, chemical restriction, irrigation management and pasture breeding are considered. None of these areas of research are looking to increase production directly through increased inputs, but, rather, they aim to lift maximum potential production, defend against production decline or improve the efficiency of the resource base and inputs. Technology approaches consistently focus on improving efficiency, while genetic improvement or the use of complementary forages and species diversity aim to lift production. These approaches do not require additional labour to implement, but many will require an increase in skill level. Only a few areas will help address animal welfare (e.g. the use of selected complementary forages and novel endophytes) and only complementary forages will help address increased competition from non-dairy alternatives, by positively influencing the properties of milk. Overall, the diversity of activity and potential effects will provide managers of pastoral dairy systems with the best tools to respond to the production and environmental challenges they face over the next 10 years. Forage management underpins the success of pastoral dairy industries. Recent dairy forage research was reviewed through a production and input loss frontier framework along with their potential impacts on competition from non-dairy alternatives, labour and animal welfare challenges. The diversity of approaches to modifying both the production and input loss frontiers will provide the tools for pasture managers to meet future production and environmental challenges. [ABSTRACT FROM AUTHOR]

Abstract: Considerable variability in the yield response of temperate dairy pastures to the strategic use of nitrogen (N) fertiliser has been observed previously. Some of this variation could potentially be attributed to environmental effects on the available N (soil mineral N plus fertiliser N) concentration required to optimise pasture growth. Five nitrogen application rate response field experiments were undertaken in an attempt to elucidate the environmental influence on pasture mineral N requirements. A significant response to N fertiliser application rate was detected in four out of the five experiments. The absence of a significant response in one experiment can be attributed to limited water availability. Across the experiments where a significant response to N fertiliser rate was detected the available N that was required to achieve 90% of maximum yield ranged between 60 and 81kgN/ha. It is concluded that when water availability, soil temperatures and air temperatures are conducive to pasture growth an available N level of between 60 and 81kgN/ha should be targeted when N fertiliser is used strategically to optimise pasture growth. Soil N testing results should be interpreted in light of the prevailing climatic and edaphic conditions if they are to be used to guide N fertiliser rate decisions within intensively managed temperate pastures. [Copyright &y& Elsevier]

Efficient nutrient management is a critical component of profitable and sustainable milk production on modern dairy farms. While the impact of intensification on nutrient surpluses at the farm scale is well recognised, there are few studies that have quantified the corresponding soil nutrient concentrations within dairy farms at a national scale. In this study, we examine soil phosphorus (P), potassium (K), and sulphur (S) concentrations on 2092 grazed dairy paddocks and animal containment areas within 43 contrasting dairy farms from all dairy producing regions of Australia. More than three quarters of the routinely grazed paddocks sampled had available P, K and S concentrations above agronomic requirements, while 20% of paddocks were at least 3 times above agronomic requirements. An exception to these generally high levels were paddocks sampled on organic or biodynamic dairy farms, which had lower soil P and S concentrations. Within farm nutrient heterogeneity was substantial, irrespective of the characteristics of the dairy farm or the regional location. Animal holding areas often had excessively high soil nutrient concentrations. Overall, there were significant relationships ( P < 0.01) between soil P, K and S concentrations and farm management and paddock characteristics including distance from milking parlour, application frequency of mechanically applied effluent, frequency of grazing herd visits, frequency of feeding of conserved forage and frequency of mechanical pasture harvesting. These results highlight generic management practises that exacerbate elevated soil nutrient concentration within grazed dairy farms and have direct implications to farmers and advisors. There are clear opportunities to strategically apply, and more often reduce, P, K and S fertiliser inputs on dairy farms without a loss of production. A greater understanding of farm nutrient fluxes and expected patterns of within-farm nutrient distribution, complemented by comprehensive soil testing, will help guide profitable and environmentally beneficial nutrient management decisions. [ABSTRACT FROM AUTHOR]