Irrigation and fertilizer application methods in horticultural crops by Dr. Kore

This slide can be useful for Fundamentals of Horticulture. 44 FC

1. Irrigation It is defined as the artificial application of water to the plants in the event of shortage of natural rains in order to obtain rapid growth and increased yield. It is an essential item in the cultivation of crops. Success in gardening depends on how efficiently irrigation is provided to gardens because it is governed by many factors such as frequency, duration, intensity, source and method of supply. Factors affecting the supply of irrigation water to plants Topography and soil characteristics. Kind of plant (root depth, water absorption capacity, growth habit, etc.). Weather condition.

2. I. Surface irrigation a. Flooding b. Basin type c. Furrow type d. Ring type II. Sub-surface irrigation a. Trench method b. Through underground pipelines c. Perforated pipelines. III. Overhead or aerial irrigation a. Sprinkler b. Revolving nozzles IV. Drip or trickle irrigation Methods of Irrigations

3. I. Surface Irrigation When the land is flat, letting in water from one end floods the entire area. This system is commonly practiced in canal or tank bed areas. It is the easiest method and permits the use of bullock drawn implements in the orchards. But in this there is wastage of water and leads to soil erosion also. It encourages growth of weeds and spread of diseases like gummosis in citrus and collar rot in papaya. a. Flooding Uncontrolled flooding Controlled flooding

4. b. Basin system In this system, circular basins are provided around the trunk of the tree. The basins are inter-connected in series and are fed through the main channel running perpendicular to the tree rows. When compared to flooding, this system minimizes the loss of water. In this system of irrigation, the water close to trunk may bring about certain diseases like gummosis and nutrients are likely to be carried over from one basin to the other.

5. c. Furrow system Entire land surface is not covered with irrigation water. The furrows are opened in the entire orchard at 4” or less apart, depending upon the age of the trees. Water is let in these furrows from the main channels. In orchards, two furrows on each side of the rows are generally made. It is suited to such lands, which have a moderate slope to the extent of 1-2% if the water is to run freely and reach the ends of the furrows. Where the slope is sharp, the furrows are made to follow the contour more or less closely. This method has disadvantage of excess of water penetration at the head than at the farther end, which may result in variation in vigour and growth of trees.

6. d. Ring system This is an improvement over the basin system. In this system, a ring is formed close and around the tree and water is let into the basin. This method is recommended for citrus trees thereby reducing the chances of collar rot to which these trees are often susceptible. The size of the ring will increase as the tree grows. In this system, the spread of diseases like collar rot, etc., are prevented. However, it involves more labour and capital and it does not permit uniform distribution of water throughout the bed or basin as in the basin system of irrigation.

7. II. Sub-surface Irrigation This system consists of conducting water in number of furrows or ditches underground in perforated pipelines until sufficient water is taken into the soil so as to retain the water table near the root zone. In limited situation, this may be a very desirable system of irrigation. In general, however, it must be used with great caution because of the danger of water logging and salt accumulation. If the sub-strata are so slowly permeable that practically no water moves through, water added may stand in soil sufficiently for long time which results an injury to the plant root due to poor aeration. Where irrigation water or the sub-soil contains appreciable amount of salt, sub-soil irrigation is usually not advisable. Land must be carefully leveled for successful subsoil irrigation so that raising the water table will wet all parts of the field equally.

8. III. Over Head or Aerial Irrigation In this system, water is applied in the form of spring, somewhat resembling rainfall. This is accomplished by pumping water from original source into the main supply line from where it is distributed to perforated pipes, which operate at low pressure (80 to 120 lb/square inch) and supply the water in a fairly uniform rectangular pattern. They have a high rate of application, usually 1”/hour or higher. Because of the high application rates, their use is restricted to soils with high infiltration rates, such as sandy or gravelly. Revolving nozzle is also at times used, which operated on either low or high pressure. Usually the rate of application followed in the rate of 0.2” to 0.3”/hour.

9. Sprinkler Irrigation May have definite economic advantages in developing new land that has never been irrigated, particularly where the land is rough or the soil is too much porous, shallow or highly erodable . It is quite useful where only small streams are available, such as irrigation wells of small capacity. It is helpful in irrigating at the seedling stage when the furrowing is difficult and flooding leads to crusting of soil. Fertilizer materials may be evenly applied by this method. This is usually done by drawing liquid fertilizer solutions slowly into the pipe. It has several disadvantages like High initial cost Difficult to work in windy location Trouble from clogging of nozzle Interference in pollination process and Requirement of more labours while removing or resetting. In general, this system is best adopted for areas where ordinary surface systems are inefficient.

10. IV. Drip or Trickle System This is the most recent system of irrigating the plants. It is usually practice for high value crops, especially in green houses and glass houses. There will be an installation of pipelines with nozzles very close to the soil. The nozzle is fitted in such a way that water is dripped almost in the root-zone of the plants. Water is allowed to move in pipes under very low or no pressure and it drop at regular interval. This system of irrigation has advantages like no disturbance of the soil; soil moisture is maintained, lesser leaching of nutrients from the soil.

11. Drip irrigation parts

12. Critical period for soil water stress for different fruit crops Fruit crop Critical period Citrus Flowering and fruit setting Litchi Fruit setting and development Mango Fruit growth onwards until the maturity of the fruit and active vegetative growth periods Pineapple Vegetative growth period and flowering Banana Early vegetative growth and fruiting Grape Vines growth and fruiting Guava Period of fruit growth Date palm Throughout the year Ber Fruit growth till harvesting

13. Relative tolerance of fruit crops of water logging Tolerance level Fruit crops Sensitive Papaya, date palm, peach, cherry, olive, citrus Moderately Banana, fig, sapota, mango, aonla , grape, guava, jamun , jackfruit, litchi Highly tolerant Strawberry, plum, ber, bael , custard apple

14. Methods of Fertilizer Application

15. Nutrients cannot be fully utilized by plant roots as they move laterally over long distances. The weed growth is stimulated all over the field. Nutrients are fixed in the soil as they come in contact with a large mass of soil. A) Broadcasting It refers to spreading fertilizers uniformly all over the field. Suitable for crops with dense stand, the plant roots permeate the whole volume of the soil, large doses of fertilizers are applied and insoluble phosphatic fertilizers such as rock phosphate are used. i ) Broadcasting at sowing or planting (Basal application) The main objectives of broadcasting the fertilizers at sowing time are to uniformly distribute the fertilizer over the entire field and to mix it with soil. ii) Top dressing It is the broadcasting of fertilizers particularly nitrogenous fertilizers in closely sown crops like paddy and wheat , with the objective of supplying nitrogen in readily available form to growing plants. Disadvantages of broadcasting

16. B) Placement It refers to the placement of fertilizers in soil at a specific place with or without reference to the position of the seed. Placement of fertilizers is normally recommended when the quantity of fertilizers to apply is small, development of the root system is poor, soil have a low level of fertility and to apply phosphatic and potassic fertilizer. i ) Plough sole placement In this method, fertilizer is placed at the bottom of the plough furrow in a continuous band during the process of ploughing. Every band is covered as the next furrow is turned. This method is suitable for areas where soil becomes quite dry upto few cm below the soil surface and soils having a heavy clay pan just below the plough sole layer.

17. It is the placement of ammoniacal nitrogenous fertilizers in the reduction zone of soil particularly in paddy fields, where ammoniacal nitrogen remains available to the crop. This method ensures better distribution of fertilizer in the root zone soil and prevents loss of nutrients by run-off. ii) Deep placement

18. iii) Localized placement It refers to the application of fertilizers into the soil close to the seed or plant in order to supply the nutrients in adequate amounts to the roots of growing plants. The common methods to place fertilizers close to the seed or plant are as follows: a ) Drilling In this method, the fertilizer is applied at the time of sowing by means of a seed-cum-fertilizer drill . This places fertilizer and the seed in the same row but at different depths. Although this method has been found suitable for the application of phosphatic and potassic fertilizers in cereal crops, but sometimes germination of seeds and young plants may get damaged due to higher concentration of soluble salts. b) Side dressing It refers to the spread of fertilizer in between the rows and around the plants. The common methods of side-dressing are: Placement of nitrogenous fertilizers by hand in between the rows of crops to apply additional doses of nitrogen to the growing crops and Placement of fertilizers around the trees like mango, apple, grapes, papaya etc.

19. Localized placement Drilling method Side dressing

20. If refers to the placement of fertilizer in bands. C) Band placement It is practiced for the application of fertilizers in orchards. In this method, fertilizers are placed close to the plant in bands on one or both sides of the plant. The length and depth of the band varies with the nature of the crop. i ) Hill placement When the crops like sugarcane, potato, maize, cereals etc., are sown close together in rows, the fertilizer is applied in continuous bands on one or both sides of the row, which is known as row placement. ii) Row placement

21. D ) Pellet application It refers to the placement of nitrogenous fertilizer in the form of pellets 2.5 to 5 cm deep between the rows of the paddy crop. The fertilizer is mixed with the soil in the ratio of 1:10 and made small pellets of convenient size to deposit in the mud of paddy fields. Advantages of placement of fertilizers When the fertilizer is placed, there is minimum contact between the soil and the fertilizer and thus fixation of nutrients is greatly reduced. The weeds all over the field cannot make use of the fertilizers. Residual response of fertilizers is usually higher. Utilization of fertilizers by the plants is higher. Loss of nitrogen by leaching is reduced. Being immobile, phosphates are better utilized when placed.

22. Application of liquid fertilizer

23. It refers to the application of solution of N, P 2 O 5 and K 2 O in the ratio of 1:2:1 and 1:1:2 to young plants at the time of transplanting, particularly for vegetables.  Starter solution helps in rapid establishment and quick growth of seedlings.  a) Starter solutions The disadvantages of starter solutions are  Extra labour is required The fixation of phosphate is higher. b ) Foliar application It refers to the spraying of fertilizer solutions containing one or more nutrients on the foliage of growing plants. Several nutrient elements are readily absorbed by leaves when they are dissolved in water and sprayed on them. The concentration of the spray solution has to be controlled, otherwise serious damage may result due to scorching of the leaves. Foliar application is effective for the application of minor nutrients like iron, copper, boron, zinc and manganese. Sometimes insecticides are also applied along with fertilizers.

24. c) Application through irrigation water (Fertigation) It refers to the application of water soluble fertilizers through irrigation water. The nutrients are thus carried into the soil in solution. Generally nitrogenous fertilizers are applied through irrigation water. d) Injection into soil Liquid fertilizers for injection into the soil may be of either pressure or non-pressure types. Non-pressure solutions may be applied either on the surface or in furrows without appreciable loss of plant nutrients under most conditions. Anhydrous ammonia must be placed in narrow furrows at a depth of 12-15 cm and covered immediately to prevent loss of ammonia. e ) Aerial application In areas where ground application is not practicable, the fertilizer solutions are applied by aircraft particularly in hilly areas, in forest lands, in grass lands or in sugarcane fields etc.

25. Foliar application Aerial application Inject in to soil

26. Doses of NPK to the applied at full maturity of different fruit trees (g/tree/year) Fruit N P K Aonla 400-500 150-200 300-500 Banana* 200-250 50-100 250-300 Ber 300-400 150-200 200-250 Cashew 300-350 150-200 250-300 Custard apple 150-250 100-1580 200-250 Guava 500-600 150-200 400-500 Grape* 125-150 75-100 125-150 Jack fruit 500-600 200-250 300-350 Jamun 500-600 200-250 300-350 Lime/Lemon 400-500 300-350 400-500 Litchi 600-700 200-250 300-400 Mango 800-900 200-250 700-800 Mulberry 400-500 200-250 400-450 Orange 600-750 350-450 350-700 Pomegranate 200-250 100-150 150-200 Phalsa 100-150 75-100 100-150 Papaya* 200-250 200-250 200-300 Saopta 500-600 200-250 350-450 * To be applied in splits