Pioneer Technical Insight

 306

Maize silage is normally sold on a standing basis with the purchaser paying for the harvesting, cartage and all subsequent costs.

The contract grower is responsible for paying for all the crop establishment costs. These will vary significantly between areas. The costs in table 1 should be used as a guide only. For up-to-date costs, please contact your local merchant and contractor.

^*Registered Trademark of Bayer CropScience.
¹ Average fertility
² High fertility

The majority of the maize silage input costs are fixed and are not influenced by the land yield potential or the area of land to be cropped. The only exceptions are as follows:

The fertiliser cost included in Table 1 is the cost associated with replacing the major nutrients removed by a 23 tonne drymatter per hectare (tDM/ha) crop. However:
a. If the anticipated yield is significantly higher or lower than this level or if soil nutrient levels are very high or very low, fertiliser input levels may need to be modified.
Recent research has indicated that dairy farm paddocks with a history of effluent application may require no additional fertiliser. Always soil test maize paddocks and apply nutrients according to results.
b. In some situations, especially where the land has been used for sheep & beef farm enterprises or continual cropping, soil fertility levels can be low. In such cases capital fertiliser is required to bring the land up to a minimum fertility level and then, the additional nutrients required by the maize silage crop must be included. Capital fertiliser cost should not be cost loaded against the maize silage enterprise as such capital fertiliser applications will result in improved soil fertility and higher subsequent pasture growth.

Most contractors have a base cost for land areas of three hectares or more. Small cropping areas attract additional contracting charges.

The cost of weighing and drymatter testing maize silage is between 0.5-1.0 c/kgDM. In some regions this cost is met entirely by the purchaser while in other regions, it is split equally between the grower and the purchaser.

Many crops are sold on a per kilogram drymatter basis with the contract being for either a set area or a set tonnage. Some crops are still traded on a per hectare basis especially in Northland and in regions where access to weighbridges is limited.

1. Per kilogram of drymatter
When a crop is sold on a per kilogram of drymatter basis, the grower benefits financially from a high yielding crop and the buyer knows ahead of time how much his silage will cost. Legally, under the Weights and Measures Act 1987 and Weights and Measures Regulations 1999, all crops that are sold on a weight basis must be weighed on a Weights & Measures approved weighbridge. This can result in increased freight charges if the trucks must detour to be weighed. There is also generally a weigh-bridge fee for each truck weighing. Some larger contracting firms have approved portable weighbridges available to customers. (Refer to last paragraph of this bulletin for information regarding the Code of Practice for the Trading of Maize Forage)

2. Per hectare
The main advantage of selling on a per hectare basis is that there is no requirement for the crop to be weighed. In some districts there are a lack of weighbridges, the disadvantage is that, depending on the crop yield, the cost to the buyer per unit of drymatter may vary significantly. For this reason many buyers prefer to purchase on a per kilogram drymatter basis.

For crops sold on a per hectare basis, the return to grower is the selling price less the establishment and any weighing and drymatter testing costs.

The returns to grower for maize silage sold on a per kilogram drymatter basis given a range of maize silage yields and selling prices are shown in Table 2.

Note that any applicable drymatter testing or crop weighing charges must be deducted from the returns in the table above. Re-grassing, capital fertiliser and land lease costs have not been included in this analysis.

In most districts, maize silage will be in the ground for 130-160 days (plant to harvest). The returns to grower are therefore 6-month returns and it will be possible to run additional grazing and/or cropping enterprises between maize silage crops.

Some farms direct drill annual ryegrass or cereals into the maize silage stubble and graze dairy cattle. Others produce grass silage for their own use or for sale. Contact your local farm consultant, contractor or seed merchant to discuss the options for your property.

Purchase agreement
A maize silage contract protects both the grower and the purchaser. Normally a deposit is collected by the grower at the time that the crop is contracted. Some crops are contracted prior to planting and this is the preferable option as it allows both parties to choose the Pioneer^® brand maize hybrid and planting population that will give the best maize silage yield.

Crop weeds
Make sure that the crop you sell is free of weeds. Weeds suppress maize silage yield and some weeds are toxic (e.g. nightshade, thorn apple). Others reduce maize silage palatability (e.g. fathen, willow weed). Some weed seed is still viable after good quality fermentation.

Collection of drymatter samples
Variations in crop drymatter occur across a paddock due to fluctuations in soil type, soil fertility, soil moisture and plant population etc. When a crop is being traded on a drymatter basis, it is important that representative samples are collected at regular intervals from the harvested material or the resultant stack or bunker is sampled using a special corer as described in the Code of Practice for the trading of Maize Forage.

The ideal maize silage harvest drymatter content is 30-38%. At this point the cob has a drymatter of around 50-60% and the stover (the green part of the plant) has a drymatter of around 20%-25%. Care must be taken to ensure that the samples that are collected contain representative amounts of cob and stover. See the "Code of Practice for the Trading of Maize Forage" for further information. A four page Guide to the Code of Practice is available free of charge from the Foundation for Arable Research, PO Box 80, Lincoln 7640, or telephone 03 325 6353, by visiting their website: www.far.org.nz or by calling the Pioneer Advice Line toll-free on 0800 PIONEER (0800 746 633).

Drymatter samples should be stored in a cool place such as a chilly-bin or fridge and submitted for analysis as soon after collection as is possible. Do not allow samples to heat and/or partially ferment, as drymatter readings will be inaccurate.

Combining Samples
Sample reduction (i.e. reducing several kilograms of samples down to 1kg sample size) can be achieved by utilising the quartering reduction method or submission of the large sample to a commercial laboratory that has a suitable riffle box designed for the purpose.

It is recommended that an extra representative 1 kg sample be kept back and stored in a freezer as a back up in case the original sample is lost in transit to the testing laboratory or a disputed dry-matter test result occurs.