Management options to recover perennial ryegrass populations and productivity in run-out pastures

Abstract

In parts of the upper North Island, farmers frequently report perennial ryegrass (Lolium perenne L.) pastures failing within 3 or 4 years post-sowing. This appears to be related to interactions between several factors: climatic (drier, hotter summers), biotic (insect pest), soil (texture, water-holding capacity) and grazing management factors that vary spatially and temporally. The efficacy of three management interventions for recovering ryegrass populations and production in runout pasture was assessed in an experiment initiated in 2018/19 in central Waikato. Treatments were a long-spring rotation (LSR), a longer grazing deferral during late spring and summer (pasture deferral, PD) and under-sowing with perennial ryegrass (US), each applied to pastures of four ryegrass cultivars. In the year after the treatments were implemented, the yield of ryegrass in PD was 2.4 t DM/ha greater than for the control (7-year-old pasture), and ryegrass tiller populations initially doubled but later declined. Yields in US and LSR were intermediate but not significantly different from the control. Ground score changes responded more positively to PD compared with the other treatments. Relative to the baseline prior to initiation of the study, tiller populations increased for PD and US but declined for control and LSR. There were no interactions between management treatment and cultivar for any of the variables measured. Pasture deferral shows promise as an intervention for recovering failing ryegrass pastures through natural reseeding. However, the longevity of the benefits observed here has yet to be determined.

Estimación de masa de forraje en una pradera mixta por aprendizaje automatizado, datos del manejo de la pradera y meteorológicos satelitales

“…En el manejo del pastoreo esto depende de ajustar la carga animal en función de la etapa fenológica de la planta, de la MF antes y después del pastoreo y del forraje que se decida dejar como remanente en la pradera. Para el ganado bovino productor de carne, la MF antes del pastoreo adecuada, se puede establecer en 2,500 kg ha -1 y la MF después del pastoreo alrededor de los 1,200 kg ha -1 (10) ; aunque estos umbrales dependerán de la etapa reproductiva y fisiológica del animal, la época del año y diferentes estrategias de manejo de la pradera para el racionamiento del alimento, el control fenológico o el balance en la composición botánica (34) . Por estas razones es importante que el modelo predictivo de MF ajuste bien en los extremos de su rango y con excepción del escenario ML_PR_MP, existió una sobreestimación de la MF cuando fue inferior a 1,500 kg ha -1 aproximadamente (Figura 3).…”

Dominant practices, information, and constraints of soil moisture conservation and nutrient management for range pastures in a sedentary grazing system in South-Western Uganda

“…In developed countries, there is increasing literature highlighting interventions that improve the productivity of range pastures (Aguiar et al, 2017;Zu Ermgassen et al, 2018;Griffiths et al, 2021). For instance, in New Zealand, range pastures have been intensively managed through increased nitrogen fertilizer application and irrigation (Whitehead et al, 2018).…”