The aim of any producer is a high yielding, high quality crop that satisfies the end user. There are a large number of factors which can influence this many are within the control of the grower, under given growing systems, climatic and soil conditions. The aim of any producer is a high yielding, high quality crop that satisfies the grower.
Soil is of three types based on its texture:
- Clay soil
- Sandy soil
- Loamy Soil
Clay soils have over 25 percent clay. Also known as heavy soils, these are potentially fertile as they hold nutrients bound to the clay minerals in the soil. But they also hold a high proportion of water due to presence of the tiny spaces between the numerous clay particles. They drain slowly and take longer to warm up in spring than sandy soils. Clay soils are easily compacted when wet and they bake hard in summer, often cracking is noticed.
Sandy soils have high proportion of sand and little clay. Also known as light soils, these soils drain quickly after rain or watering, are easy to cultivate and work. They warm up more quickly in spring than clay soils. But on the downside, they dry out quickly and are low in plant nutrients, which are quickly washed out by rain. Sandy soils are often very acidic and are not suitable for apple trees.
Loamy soils are comprised of a mixture of clay and sand that avoid the extremes of clay or sandy soils and are fertile, well-drained and easily worked. They can be clay-loam or sandy-loam depending on their predominant composition and cultivation characteristics. Loamy soils are best suited for apple trees.
Soil and water requirements
Apples trees can grow in a wide range of soils from medium textured clays to gravely sands. However, poor soils will produce poor results and the best crops are found on fertile sandy soils and loams.
Soils should be well drained. Wet soils lead to poor aeration and increased incidence of crown rot in apples. Generally, rooting tends to be shallow, and wet soils will restrict development, resulting in poor anchorage of the tree and a reduced area of soil from which nutrients can be extracted.
Soils with high organic matter contents are normally better structured and allow good rooting.
Irrigation is necessary on dry soils, particularly when establishing and growing young orchards. In young orchards fertigation helps increase early tree growth and brings trees into bearing earlier. Sprinkler irrigation can be used to protect the tree buds and fruit lets against frost damage. Sowing of grass mulch between the tree rows is common practice.
The soil pH is a measure of the acidity or basicity in soils. The pH scale at 7 is considered neutral. A pH below 7 is acidic and above 7 is basic.
Apples prefer a slightly acidic to neutral soil (pH between 5.8 and 7.0). Extreme soil pH values result in nutrient tie-up or toxicity and poor tree and fruit development. It is important to amend the pH in acidic soils by incorporating lime before planting. The optimum pH for apple is 6.5.
Orchard soils should have soil pH of about 6.5 throughout the effective rooting soil profile. Since it is not possible to incorporate lime into the soil profile of established orchards, so soils acidic in nature should be limed prior to planting. Adjust the topsoil to pH 6.5-7.0 and the sub-soil to pH 6.0-6.5.