How do I prepare my land before the trees arrive?
Plan the layout, then do only the soil, drainage and weed work that your field needs.
Good preparation helps your trees establish well, makes irrigation easier and gives your machines room to work.
How much work you need depends on your field. A suitable field may need only straightforward preparation, and you pay only for the work your land needs.
Before planting, the field is empty and you can reach every part of it. That makes this the easiest time to do the work.
Which jobs does your field need?
You do not need to do every job in this chapter. Some jobs are part of preparing every orchard. Others are for particular fields only.
| Job | When your field needs it |
|---|---|
| Plan access, rows and irrigation | Part of preparing every orchard. |
| Soil pits, and soil and water tests | Every orchard. |
| Control of difficult perennial weeds (weeds that live for many years) | Wherever the field has them. |
| Levelling, drains or berms (raised strips of soil along the rows) | Where wet conditions need improving. |
| Deep ripping (also called subsoiling) | Where there is a restricting layer (a layer that stops roots and water) that your equipment can reach and break. |
| Lime or gypsum | Where your soil assessment recommends them. |
| Washing salts out of the soil | Where tests find a salt problem and the drainage allows it. |
The order of work
Do the permanent work first and the work that is easy to change last. There are four stages.
- Plan. Find out the land history, dig soil pits, arrange soil and water tests and make a weed map. Then plan the row layout, the irrigation, the drainage and the access together, as one design. Draw it before you start any work.
- Do the necessary heavy work. Do only the jobs from the table above that your field needs. Control the difficult perennial weeds in this stage too, while you still have full access to the field.
- Install the infrastructure. Build the irrigation first, then the roads and headlands (the strips at the end of the rows where machines turn). This order avoids damage to finished work.
- Mark the final tree positions and check the system. Stake the rows and the tree and pollenizer positions (a pollenizer is a variety planted among the main variety to supply pollen). Then test the irrigation and the drainage with real water.
Planning and marking are two different jobs. You decide the layout early, because the irrigation, the drainage and the roads all depend on it. You mark the final tree positions in the field only at the end, when the heavy work and the infrastructure are finished.
Work backwards from your planting date
Start from the month when you want to plant and count backwards. Allow settling time after substantial earthmoving, such as levelling, filling or building berms, because moved soil settles. A field that needs little or no earthmoving does not need this time.
For substantial earthmoving, do the main work in late summer or autumn, when the soil is dry. Let the soil settle over the winter, then make small corrections in spring. Build the berms after the other soil work, also in autumn, so that they settle over the same winter.
Dig soil pits
Do not dig one good pit in the best corner of a 50-hectare block and then stop. Dig in the good areas and in every area that may have a problem:
- low spots
- places where water stands
- cut and fill areas (places where soil was removed or added when the land was levelled)
- road edges
- patches of heavy soil (soil with a lot of clay)
- anywhere the plants look different from the rest of the field.
What to look at in every pit
- How deep the good soil goes. This is the volume of soil where your roots will really live.
- Sudden changes in texture. Where a sandy layer lies on a clay layer, water stops and stays above the change. That trapped water stays around the roots.
- Dense or massive layers. Massive means solid, with no visible structure. Look for a hard pan (a very hard layer), a clay pan (a layer of dense clay) or a compacted zone (soil pressed hard). Note the exact depth and thickness of each one.
- Grey colours, orange mottles (spots), seepage (water slowly leaking out of the soil) or standing water. These are signs that the soil is saturated (completely full of water) for part of the year.
- Stones, gravel, buried rubble or old fill. These reduce your usable area, or need a different design.
- Salt crust on the surface. Test the chemistry by depth before you decide anything.
Use your soil and water results
Chapter 1, Site Selection, explains how to arrange a soil analysis and a water analysis. Use the results to decide what the soil needs before planting, how much to apply and when. You do not need to read the numbers yourself. The laboratory or an adviser can explain them.
Label every sample with the date, the zone, the pit and the depth, and keep a map of where each one came from. A laboratory report with no map is worth very little.
Four questions for the laboratory
- Does the soil need anything before planting?
- Which material should be used, and at what rate (how much for each hectare)?
- How should it be applied or mixed into the soil?
- Does the irrigation water need any special management?
Drainage
Many fields drain well and need no extra work. Check yours in the pits, and after rain or irrigation. Where water stands, the options below help.
You can plant a tree on a berm (a raised strip of soil built along the row to lift it above wet ground). A berm does not fix a blocked outlet, an impermeable layer or a badly designed irrigation system.
A blocked outlet means that the water has nowhere to leave the field. An impermeable layer does not let water through. Find out which of these problems you really have before you decide that earth moving is the answer.
| What you find | What to do about it |
|---|---|
| Water standing on the surface | Measure the ground levels, find which way the water flows, and make sure there is an outlet for it. Level out the low spots that cause harm. |
| Water trapped above a clay layer | Check your pits after rain or irrigation. Break the layer only if breaking it will really work, and combine it with surface or buried drainage. |
| A high water table (underground water close to the surface) across the whole site | Monitor it through the season and get qualified local engineering advice. Berms help locally, but they do not lower a water table. |
| Heavy soil and wet crowns | Plant on berms, improve water entry into the soil, and water for shorter periods, more often, instead of for long periods. |
| Cut and fill areas | Treat these as separate zones. Fill behaves differently from undisturbed soil, and it settles. |
Level the field to guide the water, not to make the field look flat. Keep the drainage routes open. Do not let fast water gather in one place where it will cut into the soil. Do not build a road or a bank across the bottom of a slope, because it will dam cold air as well as water.
After the earthworks, dig a few pits again. Cutting and filling creates a new soil map.
Never bury cut branches, tree stumps or turf under the fill (the soil you add to raise the level). Buried plant material rots without air and produces gases that can kill young trees.
Deep ripping
Rip only where your pits show a real restricting layer that your machine can reach and break. Ripping means pulling a strong blade through the soil to break up hard layers. Do not rip because you own a ripper.
Three principles guide the work. Identify the layer, work when the soil is dry enough to fracture, and inspect the result. Let the pit decide whether work is needed and how deep it should go. There is no standard depth.
| What your pits show | What to do |
|---|---|
| Deep, uniform soil, no restricting layer | Deep ripping is not needed. Do not pay for work you do not need, and do not destroy good soil structure. |
| A layered soil profile (the layers of soil from the surface down), a hard pan or a clay pan | Deep ripping or slip ploughing may be needed. Slip ploughing uses a heavy plough that cuts into the clay layer and turns it over. Decide the depth and the direction from the pit, before the machine starts. |
| A clay pan that closes up again | Clay can flow around a normal ripper’s blade (tine) and close again behind it. A slip plough lifts and breaks the clay layer instead, and works better here. A deep mouldboard plough also works better than ripping, because it mixes the clay layer into the rest of the soil. |
| Shallow rock, gravel or impermeable material | It is usually not worth ripping here. Change your layout, or leave that zone out of the orchard. |
| Wet or plastic soil (soil that sticks together and can be shaped by hand) | Do not rip at all. Wet soil sticks together instead of breaking into pieces, and you make the problem worse than it was. |
Then protect what you fixed
Heavy machines can press the ripped soil flat again, especially when it is wet. Plan the routes where machines will drive. Finish the main roads and headlands before the final work at the tree positions, and keep loaded trailers off moist planting rows.
Lime, gypsum and other soil treatments
Use a soil treatment only when your soil assessment recommends it. The laboratory or adviser tells you which material to use and how much. Salt and sodium are two different problems, and they need two different answers.
When the tests find a problem
- Acid soil: lime. Lime raises the pH of acid soil. Use the amount that the laboratory recommends, and mix it into the soil to the depth that needs it. Do not apply lime to soil that is already high in lime.
- Sodium-affected soil: gypsum. Sodium damages soil structure and stops water from entering. Gypsum supplies calcium to replace the sodium, but it does not remove the sodium by itself. The released sodium still has to be washed out through soil that drains. Use the amount of gypsum that the laboratory calculates, and do not use gypsum as a routine treatment for heavy soil.
- Salty soil: washing the salt out. Good-quality water can push the salt down and out of the root zone (this is called leaching). This works only if water can enter the soil and leave through a drain. Ask the laboratory or an adviser before you plan it.
- Chalky soil with a high pH. Iron, manganese and zinc become hard for the tree to absorb. Spreading a small amount of an acidifying product (one that makes soil more acid) on the surface cannot change a very chalky root zone. Mark these zones. Ask the laboratory or an adviser how to feed the trees with micronutrients (nutrients that the tree needs in very small amounts).
Organic matter and fertilizer
- Organic matter and compost. These improve the soil, but they do not break a hard pan, drain a wet field or remove sodium. Check the material you buy for salt, weed seed and contaminants before you spread it.
- Fertilizer. Base the choice on a soil test. Do not use a general N–P–K blend (a fertilizer with nitrogen, phosphorus and potassium) instead of a test.
- Phosphorus, potassium and zinc. These move very slowly in soil. If a test shows a real shortage, it is easier to mix them into the future root zone before planting. Established orchards have other ways to apply nutrients, including fertilizer supplied through the irrigation system. Chapter 8, Fertilization, covers feeding an established orchard.
Weed control before planting
Difficult perennial weeds are far easier to manage before the trees are planted. After planting, the trees and the drip lines block your access and limit your options. Weeds compete most in the first four years. They take water, nutrients and light from young trees. They also block your emitters (the small outlets on the drip lines that release the water) and make the harvest harder.
Work in four steps:
- Find the difficult patches. Walk the block and mark where each patch starts and ends. Include the field edges, ditch banks, wet areas and road edges. New weeds come into the field from these places.
- Choose a control method that suits each weed. The list below gives the main groups. Herbicide registrations differ in every country and change every year, so check what is legal and registered where you farm.
- Check for regrowth. A field can look clean straight after cutting or cultivation while the underground parts of the weeds are still alive. Go back to your marked patches and look for new growth.
- Repeat the treatment where necessary. Plan the follow-up checks before you start, and write the plan down.
The main groups of difficult weeds
- Field bindweed (Convolvulus arvensis) and other deep-rooted perennial broadleaf weeds. Clear or contain the mapped patches now. The roots survive any treatment that only reaches the surface.
- Bermuda grass (Cynodon dactylon), Johnson grass (Sorghum halepense) and other creeping grasses. One treatment will not remove them, so expect to treat them more than once.
- Nutsedge (Cyperus species). Where you find it, look for the wet spot or the leaking emitter that helps it grow. Fix the cause as well as the weed.
- Annual weeds. Weeds that live for one year are easier to manage, but do not let them produce seed. Every year in which they produce seed makes the first four years harder.
Irrigation, roads and headlands
Plan the irrigation and the rows together at the start. Then build in this order: the irrigation system, the roads and headlands, and last the marking of the rows. Each job is far harder to change once the next job is finished.
Install the irrigation system first
Before planting day, install and test all of these:
- the water source connection
- the pump and filter station
- the mainline (the main pipe)
- the submains (the smaller pipes that branch from the mainline)
- the valves
- the pressure and flow gauges
- the flush points (the places where you flush dirt out of the pipes)
- the crossings.
Irrigation design and row layout are one plan, not two separate jobs. Your tree spacing decides the length of the laterals (the drip pipes along the rows). It also decides the number of emitters and how much water each zone needs in the peak month.
Your soil and water results decide how evenly the water must be delivered and how much extra water you need for leaching. If you plan the rows first and the water second, you get badly balanced zones, or you have to cut trenches through planted rows.
Build the roads and headlands before planting
Set the headland width from the turning circle of your largest machine. The turning circle is the space a machine needs to turn around. Your machines may include a sprayer, a shaker (which shakes the nuts loose), a sweeper (which gathers them into rows), a harvester and a trailer. Measure the turning circle. Do not guess it.
Decide where the harvest will be loaded. Keep access open for drain inspection. Do not put a permanent road where it blocks water or cold air.
Mark the final tree positions last
Mark the row centre lines, tree positions and pollenizer positions. Check them against the headlands, roads, drain buffers and irrigation zones. Do this only after the survey, the earthworks and the infrastructure are finished. Then measure the net plantable area and check your final number of trees against it. The plantable area is almost always smaller than the area you calculated from the size of the field.
Reserve your trees and plan the delivery
Reserve your trees while you prepare the land. We plant good varieties and their pollenizers seasons in advance. An early talk helps you get the variety you chose and not what is left over.
- Talk to us early. Tell us which varieties you are considering and roughly how many trees you need.
- Prepare the field. Do the jobs that your field needs.
- Agree the delivery with us. Set the delivery date when the preparation is nearly finished, so that the trees arrive when the field is ready.
If the work takes longer than planned, tell us as early as you can. Earthworks and a wet winter are common reasons. We will talk with you about the delivery. Do not plant in a field that is not ready. The ordering guide explains how an order works.
Before the trees arrive
Walk the field and check each item yourself. Your field is ready when you can tick all of them.
Readiness checklist
- The soil and drainage work your field needs is finished. Run water through the system and watch where it goes. There should be no ponding (water standing on the surface) and no blocked outlet. Check that any berms have settled, are straight and are not in the path of concentrated runoff (fast water that gathers in one place). After earthworks or ripping, dig a pit and look at the soil. The only proof that the work succeeded is what the soil looks like afterwards.
- The difficult weeds are controlled, and the follow-up is planned. Go back to your marked patches and look for regrowth.
- Water is available and the irrigation system is checked. Test pressure, flow and uniformity across the block, not at one valve.
- Access and turning space are confirmed. Drive your largest machine down a headland and around a corner.
- Tree and pollenizer positions are marked. Check the stakes against your planting map, including the pollenizer positions.
- Tree quantities, delivery and planting arrangements are confirmed. Confirm the delivery date, the planting crew, and where the trees will be kept if planting is delayed by weather.