B+LNZ-funded research has shown that some simple changes to pasture management could help farmers make better use of rainfall and build resilience before dry conditions hit.
That was the focus of Catch the Rain, a farmer-led research project funded by Beef + Lamb New Zealand (B+LNZ) and led by Quorum Sense.
For non-irrigated sheep and beef farms, rainfall is one of the most important resources. But rain falling on a farm does not automatically mean more soil moisture and pasture growth. If soils cannot absorb rainfall effectively, water can run off rather than soak into the soil.
More than 60 farmers across the South Island and lower North Island contributed to the project through workshops, interviews and on-farm trials, with 11 farmers testing practical, low-cost ways to improve rainfall infiltration on their own farms.
“The value of Catch the Rain is that it has tested practical management changes in real farm environments. Farmers can now see where there is potential to improve rainfall infiltration and, importantly, have a way to test what works for their own farm,” says Dr Suzi Keeling, Head of Science and Research at B+LNZ.
“Being part of Catch the Rain opened up a totally different way of looking at soil for us. Learning about Visual Soil Assessments and how soil structure influences rainfall infiltration was really interesting” says Banks Peninsula farmer Will Johns.
What did the research find?
Three approaches were tested:
- Longer pasture recovery periods
- Applying a biostimulant to support soil biology
- Establishing more diverse pastures
The strongest result came from longer pasture recovery periods.
On three farms, infiltration rates almost doubled on average within nine months compared with control areas. Longer recovery periods are a relatively low-cost change that can be introduced into existing farm systems without capital investment. In the trials, farmers compared standard rotation lengths (i.e. 30 days) to extended recovery periods ranging from 60 to 90+ days.
“The results show that farmers don’t necessarily need major investment to make a difference. Longer pasture recovery periods are a relatively simple change, and the trials showed a significant improvement in infiltration on the farms involved,” says Dr Keeling.
The biostimulant trials, using a Biomarinus fish hydrolysate product, also showed positive results. Infiltration increased by about one third within just nine months on three farms, while soil analysis showed increased abundance and activity of fungi.
Sam Lang, Project Lead for Catch the Rain says “The farmers chose practices intended to deliver other benefits alongside improving infiltration, such as carrying more feed into summer or improving nutrient cycling. Finding system or practice changes that deliver those kinds of win-wins is important to maximise the short- and long-term benefits”.
The diverse pasture trials were less conclusive. Infiltration fell during the trial period, reflecting the short-term disruption to soil structure caused by pasture renewal, but longer-term benefits still need to be assessed.
Dr Gwen Grelet, Science Lead for Catch the Rain says “What was really encouraging was that we could detect measurable changes in soil function within less than a year, using relatively simple management changes. These were small, farmer-led trials, so we need to be careful about generalising the results, but they provide a strong reason to keep testing these approaches across different farms, soil types and climates.
Measure before making changes
One of the key messages from Catch the Rain is that farmers can first find out how their soils are performing before making changes.
Project workshops found that while farmers understood many of the factors affecting infiltration, most had never measured infiltration rates and were unsure whether they had a problem or what they could do about it.
Simple infiltration tests can provide a starting point. Because infiltration varies between paddocks and seasons, farmers should take multiple measurements and monitor under similar conditions each year.
The project found autumn infiltration rates were, on average, more than twice those recorded in summer, highlighting how conditions can influence results.
Turning research into practical tools
For B+LNZ, the value of investing in Catch the Rain is about giving farmers better information and practical tools to make decisions that suit their own farms.
“This research is about giving farmers better information to make decisions. By measuring infiltration and testing changes on farm, farmers can build an understanding of what works for their soils, rather than relying on a one-size-fits-all approach,” says Dr Keeling.
Improving infiltration can help make better use of rainfall, while also reducing surface runoff and soil erosion.
For farmers, the takeaway is simple: measure what is happening on your farm, test practical changes that suit your system, and use the results to build resilience.
More information and resources about Catch the Rain can be found here.