Selecting Your Cultivar

How to select your cultivar

When it comes to selecting what pasture you want to grow, the first thing you need to know is what sort of paddock you are sowing.

A few things you need to know are the pH level, the fertility status of the paddock, the topography, moisture content, the animals you are going to graze, the time you are going to graze the cultivar, what pests you have, how big is the paddock, how long you are going to graze the pasture and how you are able to sow it.

These things will affect what cultivar you choose because, for example, if it is a steep paddock that you can’t get a tractor onto, you will have to sow the seed by helicopter.

If you have a high moisture content you will want to select a cultivar like Italian Ryegrass as it can handle a lot of water whereas if it is a dry paddock you want to sow a crop like lucerne as it thrives in drier conditions.

If you want to graze lambs on a crop you would be better off sowing swedes instead of kale. This is because kale is harder to digest for lambs as they have different digestive systems.

Step By Step: A step by step method of how to select

a cultivar for your particular paddock, according to the PGG Wrightsons page:

If you have an extensive farm in Central Otago, the chances are your soil fertility levels are low, so you would be better off going for a long term cultivar and would be set stocked once the pasture has grown.

What is an endophyte? Most perennial ryegrass plants in New

Zealand pastures contain a fungus called an endophyte. Endophytes grow inside the plant and are passed to the next generation via the seed. Endophytes protect the plant from insect attack but can also cause animal health problems. Sowing treated seed in insect-prone areas is essential to protect seedlings for a few weeks after germination when the endophyte is not active against insects.

Why is it important to select a certain pasture?

It is important to a select a pasture suitable for your farm. This takes into account, your climate, your soil type and what sort of country the farmer has in general.

This means that you can maximise pasture which means the farmer can maximise stock weights and therefore maximise income.

What Is a Pasture? In NZ a pasture is usually a mixture of grasses,

legumes and weeds growing together. This is often referred to as a sward.

The types of plants growing in pastures, their nutritional value and sustainability for different livestock depends on the environmental factors like the stock that the farmer has, the climate, topography etc.

Pasture production is expressed by how much pasture can be grown per hectare per day. Its nutritional value is how much energy or protein it contains and its digestibility.

Knowing your soil Knowing what type of soil you have got is one of the most

important things to know. This is because, if you know that your soil is lacking something like nitrogen, the farmer could sow clover. This is because clover is a nitrogen fixing plant. Clover have a symbiotic relationship with Nitrogen fixing bacteria in nodules on their roots. These bacteria ‘capture’ nitrogen from the air to make into chemical compounds needed for bacterial growth. The clover ‘fix’ more nitrogen than they require and some ‘leaks’ into the surrounding soil, supporting other plants surrounding the clover. These nitrogen fixing nodules (which are situated on the roots of the plant) can be used by the clover to make amino acids and proteins for its own growth. The other good thing about clover is that white clover plants are made up of a series of stems called stolon's that grow along the soil surface. These have nodes from which leaves, roots and buds develop. Growing points are found at the end of stolon's , which are very close to the soil surface, and this means that they are protected from damage during intensive grazing. However red clovers are not like this, they can only handle light grazing and when eaten right down to the ground, may not grow back.

Nutritional Value As a farmer, you want to make sure you

always have quality and quantity, this is why selecting what sort of cultivar you want is important so that when your stock go onto the pasture, they are getting the best feed they can possibly get and making sure there is plenty of it.

The type of cultivar Once the farmer has looked at the type of paddock

he wants to sow out, he needs to decide whether or not he wants to put in an annual pasture or a perennial pasture.

An annual pasture is a pasture that will only last one year, so it is very much temporary. This may be used to fatten stock as it may be a higher yielding pasture than a perennial. However this can also mean that it is higher maintenance as it may need more fertiliser applied to give it a boost.

Perennial pastures are used as a long term investment. They may not be as high of yield as a annual but it is very low maintenance. A perennial pasture can be used up to 20 years if taken care of.

What is Most Important?

Although selecting the type of cultivar is very important, there are also other important things to do when sowing a cultivar. Things like preparing your seedbed and actually sowing your seed. You need to prepare your seedbed very well so that when the seeds are sown, it is easy for them to strike, meaning that you will get in return the quantity of good nutrition needed. Of course you need to sow your seed otherwise nothing will grow and the farmer will not be able to get any returns from that paddock, that year. Also once you have selected what cultivar you want to sow, you need to ensure that you are getting quality seed because if they aren’t any good, your strike rate will be poor and you wont get the quantity or quality of nutritional value needed.

Pest Control

Once your cultivar has grown you need to make sure pests are not going to affect it. Pests like, rabbits, deer or pigs can be managed by shooting or poisoning with 1080. There are also pests like aphids, white butterfly or slugs. These can be eradicated with poisons generally in a spray form to keep these pests away. However to ensure pests like slugs stay away, when sowing the seed, apply poisons like ‘slug bate’ to eradicate the pest from eating your cultivar.

Fertiliser Application

How do you apply fertiliser?

Fertiliser is generally applied to farmland by either a bulky or a plane. There are different ways of applying fertiliser to suit the type of the paddocks you have.

If the farmer has a very flat farm/paddock, it is cheaper to get a bulky to sow the fertiliser as it is simply sown out the back of the truck.

However if the farmer has steep hills that he wants fertilised, they will have to be top-dressed by plane. This is more expensive than getting a bulky to do it but, the plane can access more land mass than the bulky as it is sown out the bottom of the plane.

The farmer can also apply fertiliser by direct drill, (this has to be in the form of a solid fertiliser) this is a very direct way as it applies the fertiliser straight to the roots whereas fertiliser applied by bulky or plane is only on the surface of the soil and has to have water applied so that it can be absorbed by the soil and roots of the pasture.

This is why liquid fertilisers can be popular as the product does not need to be dissolved and can be absorbed by the soil and roots of the plants straight away.

Why do you Apply Fertiliser

Farmers apply fertiliser because it improves the soil, which will enhance pasture growth, which results in heavier stock to be sold off.

Application of nitrogen fertiliser such as Urea at moderate levels can also help maintain leafy pasture and increase the protein content of plants.

Fertiliser could also be applied to add trace elements to the soil, and this will improve the health of the stock that eat the pasture.

How does fertiliser effect Pasture Growth? Different fertilisers do different things to the

soils. When stock eat the pasture they are depleting

the soil of nutrients like phosphorous. This then needs to be replaced in the form of fertiliser.

When fertiliser is applied (in solid or liquid form) it gets dissolved when it rains and is dissolved by the water, it flows into the soil. This is then available to the roots of the pasture to absorb these nutrients out of what now is in the soil to maximise growth in the pasture.

However if you apply to much fertiliser it can do no good.

If you apply to much fertiliser the farmer will scorch the soil meaning no pasture will grow. This happens when the soil becomes to acidic for any growth. To fix this, apply lime to make the soil more alkaline as the optimum pH level is from 6-6.5

Also if you apply to much fertiliser to the soil, it can leach. This mainly happens on dairy farms as dairy farms generally apply more nitrogen than sheep and beef farms because generally dairy farmers are on heavier soil and get a better response. Dairy farms are also more intensive than sheep and beef farms so they need more nitrogen to keep the grass growing to its full potential.

When nitrogen leaches, it can get into water ways and encourage growth of algal blooms. Algal blooms suck all of the oxygen out of the water which suffocates the fish and any marine life in the water.

Soil Structure Applying fertiliser definitely boosts pasture

growth, however if you have a good soil structure it also helps a lot to boost pasture growth.

Good soil structure is when the soil is well aerated,(plenty of pores in the soil means the soil can heat up easily) and well drained,(the pores are the right size to be able to hold water and not leach to much).

This good soil structure can be achieved by ploughing the soil. This breaks down down any hard pans in the soil so that it is easier for pasture to grow its roots, and push up through the soil.

Why is fertiliser so important? Applying fertiliser is the most important thing to do,

(equal with irrigation) to maximise pasture production. Applying fertiliser, and irrigating are the most important

things to do on a farm as, because the stock are constantly eating the pasture, the goodness and minerals are all being taken out. (the only thing being put back into the soil naturally is urea which is nitrogen). This is why we need to apply fertiliser to put the goodness/ minerals back into the soil to keep the pasture healthy and growing to its full potential.

Irrigation is also very important as plants cannot perform photosynthesis without it. If the soil does not receive enough water to perform photosynthesis, the soil will go dry and will crumble very easily, and the pasture will also not perform to its full potential and can start to die.

Comparison: Fertiliser and lime do two totally different jobs to the

soil. Lime conditions the soil and raises the ph to make the soil more basic. Lime also helps to release built up phosphorous that hasn’t been used to promote growth. Whereas fertiliser supplies nutrients for the pasture to absorb and then grow vigorously, so that there is more pasture for the stock to eat, there for making it easier for the farmer to reach their target weights. So although I believe applying fertiliser is more important than liming, if the farmer has enough money to lime at the same time as apply fertiliser , he should as both the products compliment each other to enhance pasture growth.

Controlled Grazing Systems

What is the aim of having grazing methods?

Grazing methods aim to control stocking rates, the time a paddock is grazed, the interval between one grazing and the next and the pasture height before and after grazing.

This is especially important when new pasture is being established as it is very easy to damage it.

Pastures are vulnerable to overgrazing, if the stocking rate is too high or they are left to graze the pasture to too long.

If it is regrazed too soon the pasture will not have time to replenish their root reserves (through photosynthesis in the grazed off leaves) and may die.

Grazing methods such as rotational grazing are very important throughout the winter as this is when farms are short on pasture and when having well controlled grazing systems, all pasture can be utilized.

What are some different grazing Systems?

Grazing management has a major influence on pasture quality . There are several types of methods used in NZ farming depending on what animals are grazed and the type of land being farmed and production goals.

Rotational grazing Set stocking Mob stocking Creep grazing Subdivision Break Feeding

Subdivision - subdividing the farm into smaller areas allows tighter control of both animal pasture intake and pasture regrowth. Permanent subdivision with fixed fencing and temporary subdivision (break fence) are two methods. Break feeding pasture behind an electric fence forces stock to eat pastures to target residuals.

Set Stocking – this is also called continuous grazing. They are placed in a paddock with relatively low stocking rates and are moved off occasionally. The paddocks may be rested for periods from a few days to several weeks.

Rotational Grazing – a farm is divided into paddocks and all animals in a mob graze one paddock for a brief period (up to a week depending on the size of the paddock) before being moved into the next paddock on the rotation.

Break Feeding – Break feeding involves partitioning a paddock of pasture or crop, usually using an electric fence, into an area large enough to meet animals targeted feed requirements. The animals typically stay in the area for no longer than 24 hours. This method is typically used in the winter to make sure the stock are getting the right amount of feed they need. It is also very often used when feeding a crop to your stock.

Creep Grazing – creep grazing is when young nursing animals are given forward access to fresh, ungrazed pasture through an opening in the fence. The forage in the creep area must be superior than in the non-creep area to boost nutritional value to the younger stock.

In comparison: In comparison to the other harvesting options, I believe

having good controlled grazing systems is the most important as, if the farmer goes through a hard season he will be running low on pasture if he doesn’t have good grazing systems in place. But if the farmer has been very good in controlling where his stock have been grazing, he should not need to harvest and store pasture for the winter. This is simply because he will have controlled how much pasture the stock have needed therefore using the pasture to its full potential. I also believe that controlled grazing systems are the most important as when you harvest and store pasture to feed out to stock over the winter or just when the farm is low on feed; the quality of the pasture decreases dramatically meaning that you are better off feeding pasture when it is live rather than when it has been harvested and stored for length of time.

By Ryan Neill