Whole crop cereal silage

These trials began in Autumn of 2014 and are investigating how crop management can be used to optimise yield and quality factors and predict harvest time with more certainty are on-going.

Trials in Waikato and Canterbury will assess the best fit for cereal silage in sequence with other crops to maximise annual productivity.

Autumn sown whole crop cereal silage 2014-15 Key points

  • Oats are more suited to a green chop harvest than a direct chop, while triticale and wheat performed well at both harvests. Barley had the lowest green chop yield.
  • Crops gained an average of 310 kg DM/ha/day after flag-booting, so every day counts (but don't miss the harvest window).
  • The first consideration for crop selection is the fit for the rotation.
  • The second consideration is a tricky balance between yield and feed quality:
    • This season, barley yield was comparable to wheat and had a much higher proportion of grain
    • PGR may be able to enhance feed quality in some cases

Whole crop cereal silage is a high carbohydrate-low protein feed supplement to pasture for dairy cows. Much of the cereal silage grown is sown in the spring, but an autumn planting provides a higher yield potential, so trials in the 2013-14 and 2014-15 seasons have looked at how management inputs affect DM yield, feed quality, and harvest window of autumn sown cereal silage crops.

Results from the 2013-14 trial indicated that wheat was both high yielding and gave the most flexibility in the harvest window. The 2014-15 trial was therefore designed to look more closely at wheat and to determine how yield and quality components were affected by PGR inputs over wheat cultivars with different maturities and heights.

Five wheat cultivars (Wakanui, Raffles, Torch, 09-25*, and 12-45*) were tested alongside oats (Coronet), triticale (Prophet), and barley (Sanette). Plots were sown at Lincoln, Canterbury on 7 May 2014 and later harvested for DM yield and quality at three timings: flag-boot stage (green chop), 38% DM (direct chop), and at grain maturity.

At green chop harvest, oats and triticale yielded the highest (4.9 and 4.5 t/ha), while triticale and wheat were the highest yielding at the 38% DM harvest (23.2 and 21.4 t/ha). No differences were seen in yield between wheat cultivars at either harvest.

From flag-booting to the cheesy dough stage (~38% DM), the estimated change in biomass averaged 310 kg DM/ha/day and 840 kg/ha per change in DM%. Wheat and triticale put on the most biomass per day and per increase in DM%. Cereal species was the most important factor contributing to the ratio of head to total biomass at direct chop harvest as well as the harvest index at grain maturity.

The PGR regime was only able to improve these characteristics in certain cultivars. Barley had the highest harvest index. It is important to keep in mind that in a direct chop harvest, the grain component is the most important contributor to feed quality characteristics such as digestibility and metabolisable energy (ME). While some crops may be higher yielding than others, it is the grain portion that drives quality, so a good balance of the two is needed when deciding what to sow.