Approximately one third of all Australian commercial scale farms across Australia produce hay each year. Export quality oaten hay demands a price premium but achieving quality standards set by hay buyers along with optimal yields can be tricky.
BCG is currently running its second of three years of trial work as part of the National Hay Agronomy project, funded by Agrifutures. A trial has been established at Rupanyup, in the Wimmera, with two sowing times, nine oat varieties and six nitrogen rates. Treatments are outlined in the table below:
Table 1. 2020 Oaten hay trial treatment outline. Nitrogen applied two thirds at sowing and one third six weeks post sowing.
|Variety||Time of sowing||Nitrogen Rate (kg N)|
The trial aims to increase understanding of how agronomic management can influence hay yield and quality for the export market. Key export markets for Australian hay are Japan, Korea, China and Taiwan.
Hay exporters take a subjective and objective approach to determining hay quality.
In the paddock exporters will generally look for subjective indicators such as:
- Stem thickness
- Roughage or texture
Hay quality is also objectively measured through feed analysis testing looking at key indicators such as:
- Sugar levels (water soluble carbohydrates, WSC)
- Neutral Detergent Fibre (NDF)
- Acid Detergent Fibre (ADF)
- Digestible dry matter (DDM)
ADF refers to the cell wall portions of the forage that are made up of cellulose and lignin. These values relate to the ability of an animal to digest the forage. As ADF increases, digestibility of forage usually decreases.
NDF values reflect the amount of forage the animal can consume. As NDF percentages increase animals will generally eat less due to the rising fibre content which takes longer to digest in the rumen.
“Basically, when we are looking at export quality hay we’re looking for a product that’s high in sugar with low fibre. NDF at 50% or below and ADF 30% or below is exceptional.” explained Brad Kelly, Product Acquisition at Mallee Hay in Ultima. “Essentially, we want a thin stemmed, soft texture hay. Thin stems are generally sweeter and higher in sugar. A soft textured plant is more palatable and sought after in international markets”
Thinner stems with lower fibre and higher water-soluble carbohydrates make better quality hay, therefore sowing rates for oaten hay are comparatively higher than oat crops taken to grain.
The trial at Rupanyup is sown at a target of 320 plants per square metre to achieve this smaller stem diameter, there is natural variation in this diameter between varieties. For example, Vasse, released in 1997 is generally not preferred by hay producers due to its coarse stem diameter.
“We encourage growers to sow at reasonably high rate around 100-120kg per hectare and to get their row spacing as low as they can – if you’re on 10-12″ spacing or higher we recommend that growers double sow with the second pass at 20 degree offset to create a diamonds pattern and create more competition for plants” says Brad “Higher competition during the growing season helps achieve the qualities we’re after for good export hay.”
Results from 2019 trial work showed variation in hay yield and quality across treatments. Early May sown treatments on average yielded 1.5t/ha higher than early June sown treatments. Yield in 2019 was optimised with the application of 120kgN/ha split between sowing (two thirds) and top dressing six weeks post sowing (one third).
In terms of hay quality, leaf greenness (SPAD chlorophyll measure) was higher for later sown treatments with variation between varieties with increase in greenness up to 60kgN/ha with no further response at higher N application rates. Stem thickness was reduced by later sowing and variety selection, with Koorabup and Brusher having the thinnest stems.
Seasonal differences will have a significant impact on hay yield and quality. The National Hay Agronomy project has trials established across different hay growing environments in Australia. Collectively, the national project aims to improve agronomic guidelines to maximise oaten hay production and quality.
BCG will be running a hay focussed crop walk at the Rupanyup site on Wednesday August 19th. If you are interested in finding out more about oaten hay production, keep an eye on the BCG events page on the website.