Pasture renewal on Bay of Plenty and Waikato dairy farms: impacts on pasture performance post-establishment

Abstract

To determine the impact of pasture renewal on dairy pasture performance, a total of 24 renewed and unrenewed pastures were monitored in Bay of Plenty and Waikato for 5 years. Renewed pastures produced an additional 1.5, 1.8 and 1.9 t dry matter (DM) ha −1 in the first, second and third years of monitoring, respectively, compared with unrenewed pastures. There was a greater contribution of clover, sown grasses and unsown grasses and a smaller contribution of broadleaf weeds in renewed than unrenewed pastures in some years (% of total DM). The sown grass DM content (kg DM ha −1 ), perennial ryegrass tiller densities and endophyte infection frequencies were similar in renewed and unrenewed pastures. The abundance of invertebrate pests and total nematodes was lower in renewed than unrenewed pastures in some years. The greater clover content, fewer weeds and fewer insect pests, contributed to the greater herbage production of renewed pastures.

Net changes of soil C stocks in two grassland soils 26 months after simulated pasture renovation including biochar addition

“…In regions that have long‐established grazed pasture systems and a steady state has been attained with already high soil TC stocks, it is uncertain whether these stocks can be enhanced and they could even decline under intensive grazing systems (Schipper et al ., ). As discussed in the Introduction, pastures require periodic renewal (cultivating and resowing) to maintain their productive potential (Tozer et al ., ). There is concern that, if the cultivation is too frequent, the large amount of pasture residues and SOM decomposed after cultivation (Vellinga et al ., ; Rutledge et al ., ) will lead to significant soil C loss (Curtin et al ., ).…”

“…At depth 14-16 cm, the difference between total C and the oxidizable organic C (TC -OC ox ) is indicated (■) for each treatment. Vertical bars indicate values of TC and TN for the 0-10 and 10-20 cm depths at the beginning of the experiment (T0) for the nonamended soil, as indicated in Table 1. resowing) to maintain their productive potential (Tozer et al, 2013). There is concern that, if the cultivation is too frequent, the large amount of pasture residues and SOM decomposed after cultivation (Vellinga et al, 2004;Rutledge et al, 2014) will lead to significant soil C loss (Curtin et al, 2010).…”

“…Pastures require periodic renewal (cultivating and resowing) to maintain their productive potential (Tozer et al, 2013). This often involves a short-term soil C loss until replenished by further pasture growth (Curtin et al, 2010).…”

Effects of including forage herbs in grass–legume mixtures on persistence of intensively managed pastures sampled across three age categories and five regions

“…In a postal survey of 776 dairy farmers in the central North Island of New Zealand, poor persistence of renewed, predominantly perennial ryegrass (Lolium perenne L.)-based pastures was similarly ranked as one of the most important factors limiting farm economic performance (Kelly & Smith 2011). In a recent study on the effect of pasture renewal on commercial dairy farms in the upper North Island, total annual dry matter (DM) production was greater in renewed pastures in the first, second and third years, but in the fourth and fifth years there was no yield benefit from renewal (Tozer et al 2015). Most of those pastures were based on perennial ryegrass and white clover (Trifolium repens L.) and it was thought that drought and invertebrate pests contributed to the decline in DM production of the renewed pastures as they aged.…”

Incorporation of the grazing utilization subindex and new updates to the Pasture Profit Index

“…Additionally, the breeding of new, superior perennial ryegrass varieties will surpass the performance of the previously used varieties (McDonagh et al, 2016). Regular reseeding of pasture will maximize the proportion of perennial ryegrass within swards, optimizing farm production and profitability Tozer et al, 2015).…”