Dairy NZ

Pasture management systems for Northland: Quantifying the effect of three different pasture management systems on milk production and farm profitability (funded by DairyNZ/NDDT/Ellett Trust)

Timeframe: August 2008 to June 2012

Objectives of Trial

• To compare the productivity and profitability of three different pasture management systems in Northland:
• Ryegrass
• Mechanical Control of Kikuyu ( Mulching and under sowing Italian Ryegrass
• No Mechanical Control of Kikuyu (Non Mulching and over sowing Italian Ryegrass

Expected Outcomes of Trial

• Measure the economic impact of Kikuyu control in a Northland Dairy farming system
• Develop an economic comparison of milk production on the three different farming systems
• Develop “best practice” strategies for farming with or without Kikuyu

Update:

This project has completed three seasons. An application was made to DairyNZ to continue funding the trial for a fourth year and this was accepted. The justification for this being the very dry summers we have experienced in the first two years of the trial which has not allowed the kikuyu farmlets to display what we would believe to be a typical pasture growth pattern.  In addition, we would like to determine the impact of regrassing 100% of the ryegrass farmlet on productivity and profitability within the system (the pasture growth rates and amount of supplement fed indicate that it is severely underperforming in dry matter yields).

A couple of changes have been made to the farmlets in terms of calving dates and stocking rate for the coming season. Calving dates have been changed on the farmlets to better reflect the feed availability of each system this year. Planned start of calving is now 1st of July (Ryegrass), 10th of July (Mulched) and 15th of July (Non-mulched). In previous years all farmlets started calving on the 10th of July.

The original stocking rate of 2.9 cows/ha has been adjusted downward on the ryegrass farmlet to 2.7 cows/ha. This should allow the new perennial ryegrass that was undersown on 100% of the farmlet to establish better than in previous years and with the improvements made to drainage on this farmlet we expect our supplementary inputs to be reduced. Over the last three years the farmlet has gown about 20% less feed than the other two farmlets.

The stocking rate on the mulched farmlet has been increased to 3.3 cows/ha while the non-mulched farmlet remains at 2.9 cows/ha. The rational for the difference between the two kikuyu herds is again based on pasture growth and what we expect the two farmlets to grow this coming season – i.e. the mulched farm is well set up and we expect to have a very good Italian Ryegrass take vs. a very poor take on the Non mulched farmlet and as a result growth over winter and spring on the non mulched will likely be very poor – net outcome is the mulched farm should grow considerably more DM this coming year than the non mulched – and much  more ME.

Click here for fortnightly farm walks and management notes.