Orchard plantation is a long-term process and needs a lot of care during the initial stages of growth. Ignorance during plantation cannot be corrected later. For successful cultivation of fruits, orchard soil should be in good condition. Soil for fruit plants should be deep, well-drained, loamy, fertile, and free from hard pan up to a depth of 2 meters.
The water table should be below 3 meters and not fluctuating. Water-logged, marshy, and salt-affected soils are generally not suitable for fruit growing. Soil testing is important for assessing the suitability of a selected site for fruit crop plantation. The growth and development of fruit plants is generally dependent on the plant type, soil type, climate, bearing capacity, orchard management as well as soil fertility. Excessive fertilizer application may cause an imbalance in the nutrient status of soil along with increased production costs and less profit.
Fruit plants are long-duration crops with deep roots as compared to field crops. Therefore, the knowledge about the various soil characteristics of the field, in which the orchard is to be established, must be known for the farmer to get good quality fruit and better returns. For this reason, soil testing should always be done before planting as this is the best tool to judge the suitability of an orchard plantation. Soil testing before orchard plantation gives an idea to incorporate necessary need-based soil amendments.
Method of Soil Sampling:
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Soil sampling before orchard plantation is carried out up to a depth of 6 feet (2 meters app.). 7 soil samples should be collected starting from the surface to the depth of 15 cm, 15-30cm, 30-60cm, 60-90 cm, 90-120 cm, 120-150 cm and 150-200cm. There will be two soil samples for 30 cm soil depth intervals which must be mixed if samples must be taken with the help of Augar.
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Samples from different soil depths are collected by using an auger or exposing a soil profile with the help of Khurpa or spade.
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If any hard pan or concrete layer is present, its sample should be collected separately. The depth and thickness of this hardpan or concrete layer must be noted at the time of sampling.
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About half a kg of soil sample from each depth should be taken. After collecting the soil samples, put them in a clean cloth bag along with labels inside and outside having information regarding the complete address of the farmer, field number, depth of soil, etc.
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The label should be written with a pencil/pen.
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Samples should be sent to the nearby soil and water testing laboratory Samples should be sent to the soil and water testing laboratory of the Department of Soil Science, Punjab Agricultural University, Ludhiana, and Citrus Estates of State Horticulture Department at Hoshiarpur, Badal (Shri Muktsar Sahib) and Abohar for testing and analyzing various soil parameters preferably one month before plantation of orchards as there are two main seasons for plantation i.e. February-March and September-October.
Soil testing gives information about soil pH, Electrical conductivity (EC), Available phosphorous, potassium, and organic carbon (OC) status of soil, which indicate the amount of organic matter present in the soil. Fruit plants benefit greatly from organic matter as it helps with nutrient availability by improving soil structure, and moisture retention and serving as a nutrient reservoir. Soil pH is one of the critical factors in the nutrient management.
The pH of the soil reveals a reaction of the soil that is acidic, alkaline, or highly alkaline. Most of the fruit plants perform well in soil having pH from 6.5 to 7.5, as most of the nutrients are available in this range. The citrus plants thrive best in soils having slightly acidic reactions with a pH range of 5.5 to 7.5. If soils have high acidic or alkaline nature, citrus do not grow well and there is limited absorption of nutrients from soils. The pH of the soil should not be more than 8.5 for successful cultivation of citrus. Some plants of citrus species, peach, pear, and mango cannot survive in alkaline soils. On the other hand, some fruit plants like ber, date palm, guava, and amla can perform well in soils having pH 9. Depending upon the tolerance of fruit plants to alkalinity, they are divided into three groups. (Table1)
Table 1. Groups of Fruit Plants Depending on their Tolerance to Alkalinity
|
Tolerant fruit plant |
Semi-tolerant fruit plant |
Sensitive fruit plant
|
|
Date palm, ber, amla, guava |
Pomegranate, phlasa, jamun, grapes, pear |
Citrus, peach, papaya, plum and mango |
The electrical conductivity, which is an index of salt buildup, should be less than 0.5 mmhos per centimeter for the cultivation of citrus and peach and should be less than 1.0 mmhos per centimeter for other fruit plants. The calcium carbonate and lime concretion should not exceed 5 and 10 percent respectively for the cultivation of citrus and peach and should be below 10 and 20 for other fruits.
Table 2. Suitability Limits of Soil for Plantation of Fruit Plants
|
Character |
Citrus and peach |
Other fruit plants |
|
i Conductivity (mmhos/cm) |
<0.5 |
<1.0 |
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ii Calcium carbonate (%) |
<5 |
<10 |
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iii Lime concretion |
<10 |
<20 |
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iv pH |
<8 |
Up to 8.7 Up to a depth of 60 cm only in the lower layer, however, the pH may go up to 9.0 |
The selection of fruit plants based on the soil type, nutritional status, and other conditions of soil and subsoil layers, by the orchardist is the first and significant step while planning for an orchard, which leads to high fruit productivity, more profit, and good soil health management. Therefore, soil testing must be done before the plantation of orchards based upon which selection of fruit crops for soil can be assessed as this is a long-term investment, and orchards planted without soil testing may not grow due to the presence of hardpan/concrete layers and three will be loss of farmers money and wastage of efforts put into getting better yield from fruit crops.