ORCHARDS

There are a number of commercial fruitgrowing districts in Australia each with certain advantages and disadvantages for certain fruits. Many districts can be subdivided into sub districts using soils, altitude and fruit maturing dates. The following factors affect the siting of an orchard:


SOIL AND SUBSOIL

A deep friable loam is suitable for most fruit but some prefer lighter soils. In some districts apples and pears do well on heavier soil in which peaches could not be expected to do as well. Apricots prefer heavier soils than peaches. However, deep loams are not always available and newer orchards are often established on inferior soils. The lack of fertility can be easily overcome by the application of fertilizers, the most popular being poultry manure. The class of the subsoil is important because it does not matter how good a shallow soil may be, it will be no good for fruit trees if the subsoil is heavy and almost impervious to water. Such a soil becomes quickly waterlogged during a wet period and will dry out just as quickly during a dry period.

Another reason for the importance of the subsoil is because of the increasing use of seedling stock, it is most important that a good medium be provided for their deep roots.

Successful orchards can be established on poor sandy soils for example, when the sand overlays a deep subsoil of friable clay where water can percolate freely and the roots of the tree can penetrate. This is shown by a number of successful orchards located on sandstone country near Sydney. However, very deep sands are not suitable as the moisture and nutrients rapidly percolate down beyond the reach of the roots. For pome orchards the soil must be fertile and well drained. Shallow soils overlying heavy clay, ironstone or gravel or very sandy subsoils are unsuitable for commercial apple growing.

The successful apple areas in Australia are either on granite (Stanthorpe region of Queensland) or rich basalt soils with a deep friable and clayey subsoil (Arding/Kentucky region in NSW). Provided that the granite soils are of good depth and the subsoil conditions are favourable, produce excellent quality apples, particularly of the long keeping cool storage varieties.

SLOPE

In is common practice to site an orchard on the slope of a hill to escape the detrimental effect of frosts. A slight slope has the advantage of being easier to drain away surplus moisture but excessive slopes can cause problems with operating equipment safety and soil erosion. Rocky soils may be favoured as being better drained.

SUPPLEMENTARY IRRIGATION

Supplementary irrigation is most important for all the major fruit growing ares. Because a district has high rainfall does not mean that irrigation is not necessary because the rain pattern may show a high variability. The availability of irrigation during dry periods greatly reduces risks of production. The possible sources of water include creeks, dams, bores and springs. An irrigation licence from the appropriate water authority is necessary.

ACCESSIBILITY TO MARKET

Proximity to market is most important especially for stone fruits where delays in marketing can cause heavy losses. High transport costs can make an orchard uneconomical and therefore most successful orcharding districts have good rail/road communications and access to one or more of the major markets.

SOIL PREPARATION

It is essential for the orchardist to eradicate weeds and couch grass. The soil should then be worked a number of times with a cultivator using curved tynes which works the remaining couch to the surface. This operation should be carried out while the land is dry.

PLANTING DISTANCES

There is a trend towards closer planting. Climate, particularly rainfall and soil fertility are major factors but the trend towards dwarfing rootstocks and changes in orchard practices determine this. The smaller trees mature quickly, are easier to maintain and pick, and the smaller uniform size fruit is most suitable for the export market.

Trees in good rainfall areas require a reasonable distance between them to enable proper growth and expansion of roots. They are often planted close together but the rows are spaced further apart. This applies particularly to contour ploughed paddocks when cross cultivation is impossible and the additional space between the rows allows the most efficient use of power equipment. The closer plantings of rows results in about the same number of trees per hectare.

The hedgerow planting system is particularly favoured for the "drive past" methods of spraying and when incorporated with appropriate rootstocks, varieties, irrigation and other management techniques a large reduction in production cost can result.

COVER CROPS

Most of the stone and pome fruit is grown on the coast, tablelands and slopes of NSW were the soils are subject to erosion. Whereas clean cultivation was once advocated more use is now made of cover crops and volunteer grass cover. Most orchardists maintain a cover growth during the winter months and this is usually roughly worked or mown in July or August to suppress further growth. The ground is left in a comparatively rough state until further cultivation becomes necessary.

The use of subclover in orchards has assisted in soil erosion control by improving soil fertility and preventing runoff. Organic matter plays an important part in the maintenance of soil fertility. In its virgin state, most first class apple growing land consists of a good crumbly structure plentifully supplied with organic matter.

Under any system of continued cultivation it is difficult to check losses of humus from the soil and every effort should be made to maintain and if possible increase the humus content of the soil. This can be achieved economically in most cases by growing and turning in green manure crops, preferably of the leguminous type such as clovers, peas, beans, vetches etc. Of these the self seeding clovers such as subterranean have proved particularly valuable in those districts suited to them.

Today, subterranean clovers are regarded particularly well in the high rainfall areas as a soil builder without equal. If it is not possible to grow a leguminous crop; barley, oats can be grown or even a volunteer weed crop. In areas of less reliable rainfall the volunteer weed crop, topdressed in the autumn with superphosphate is frequently the most satisfactory and economical source of added organic matter.

CONTOUR PLANTINGS AND SOIL MOISTURE CONSERVATION

Contour plantings provide particular benefit to the orchardist particularly in the control of soil erosion and the provision of water supplies. When inspecting an orchard the valuer should look for miniature washes which if left unattended, will quickly develop into gullies and creeks. The main factors in deciding whether or not an area can be contoured ploughed are the size of the orchard, number and location of depressions, and provision for drainage outlets.

Contour planning of orchards in addition to controlling soil erosion has other advantages such as allowing more water to percolate through the soil and into the subsoil.

The steeper the slope, the quicker the runoff and by reducing the slope through contour ploughing the water moves more slowly and a far greater amount is admitted to the soil and subsoil. This factor is particularly important in low rainfall areas. The block becomes slightly terraced which is an advantage from a soil erosion, maintenance and water conservation point of view.

see apple growing


DOUBLE OR HEDGEROW PLANTING (7x3.5) OF APPLES IN THE FORBES DISTRICT




OLD STYLE LARGE TREE ORCHARD







A BADLY ERODED PRUNE ORCHARD, AS THE AREA CONSISTS OF SEVERAL SMALL HILLS, THE ONTOUR BANK WITH THE TREES PLANTED ON THE SQUARE WILL PROBABLY BE THE ONLY PRACTICAL METHOD



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