Correct usage of basal fertilizers in potato fields is very crucial for high quality yields. The choice of the type and quantity of fertilizers is determined by nutrient levels of the soil. Hence it is advisable to carry out soil analysis before fertilizer application in potato fields. Poor application of fertilizers may results in poor quality yield. When potatoes are grown under deficient or excessive Nitrogen, harvested tubers are smaller, have higher sugar levels, and lower starch content than desired. Tuber maturation is also affected. Without proper N fertilization, plants are more susceptible to diseases. Excessive N can also delay tuber initiation and promote overgrowth of vines even rotting of tubers
Recommended Basal fertilizer application
Basal fertilizer is applied to potato field before or during planting. Firstly, the ridges are opened for fertilizer application. The depth of opening should be around 12-15 cm. It is strongly recommended to carry out soil test to establish the fertilizer requirement levels of your field. Farmers may consult Agricultural Extension Officers in their area who may guide them on how soil tests for their field may be carried out.
In Malawi for example in the absence of soil test; in most soils, it is recommended to apply NPK 8-18-15 + 6 S commonly called D-compound at the rate of to 400kg/ha (8 bags/ha) where potatoes are grown for seed or rate of 300kg/ha where potatoes are grown for consumption, may be used as basal application. The fertilizer is applied at the rate of about 20 g per metre of ridge length using two cup cupfuls of cup No. 5. The fertilizer is applied in the opened ridge or row. The applied fertilizer is mixed with soil using a stick while taking care not to reduce the opening depth; this operation is done to avoid direct contact between fertilizer and tubers to be placed during planting Farmers may also 23:21:0 +4S fertilizers but this not encouraged because this type does not contain all the required balanced levels of the fertilizer nutrient levels i.e. ‘0’ on the 23:21:0+4S denotes that it does not contain K which is an important element for potato tuberisation process.
Top dressing (Second fertilizer application)
A second dose of nitrogenous fertilizer such as CAN or Urea fertilizer when the crop is 14 to 21 days after planting and plant height is about 15 to 25 cm. However, in tropical regions such as Malawi it is advisable to use CAN than Urea because Urea evaporates or volatilizes when exposed to sun and also encourages more vegetative growth and watery or soft starch tubers that is very susceptible to rotting. Apply the fertilizer in the grooves in the soil surface 5 cm away from stems. Apply about 30 g of the fertilizer using 10 cupfuls of cup No.5 per metre. This mainly applies when the crop is grown for seed. For ware potatoes the grower may apply 20 g per metre of ridge length using 5 cupfuls of cup No. 5. It should be noted that too much fertilizers or too close to the plant can burn the stems and leaves of the potato plant. Also note that nitrogen fertilizer such as Urea evaporates or volatilizes when exposed to sun. This justifies why hilling up (or banking) of plants should be done immediately after second fertilizer application. Adding soil around plants helps tubers and stolons (underground stems that carry tubers) to be kept in the soil. If stolons come out of the soil they will produce stems with leaves instead of tubers. Soil test results may also be necessary to guide the farmer on the quantity of CAN or Urea to apply per hectare of land. Where no soil test exists, 200-250 kg of CAN per hectare may be applied or 150-200 kg of Urea (46%N) per hectare may be applied for potatoes grown for seed whereas 150-200 kg/ha of CAN may be applied to achieve high tuber yield. Nevertheless, it is strongly recommended that for commercial farming soil test be conducted.
The nutrient requirement of potatoes is very high. It has a shallow root system and also a very short growing period during which it must bulk up yield. Nutrients must be readily available in correct and balanced amount. Tuber quality is also significantly affected by plant nutrition. Phosphorus deficiency and Nitrogen or Potassium excesses can decrease specific gravity leading to small tubers hence low yields. Growth disruptions, because of fluctuations in nitrogen supply, can cause misshapen tubers with brown centres or hollow centre. Potassium deficiencies can result in increased black spot bruise at harvesting, darkened colour, and storage problems. Excess Nitrogen, on the other hand, can delay tuberisation and slow skin development at maturity. Vines with excessive nitrogen can create an environment more conducive to infection by certain pathogens. Calcium deficiency has been associated with internal brown spot. The potato plant has a poorly developed root system. Fertiliser is therefore mainly applied in the planting furrows at the time of planting. It should preferably be placed at the same level as, or under, the seed tubers. It is recommended that potato planters be equipped with bins for fertiliser application. If the phosphorus requirement is very high, some of the phosphorus may be broadcast and incorporated into the topsoil. The rest is then applied in the planting furrows along with the nitrogen (N) and potassium (K). Nitrogen top dressings are applied on either side of the plant row, after the rows are ridged and irrigated. Potatoes respond well to fertilizers. Being a root crop, they respond well to phosphorous and nitrogen.
Answers
Correct usage of basal fertilizers in potato fields is very crucial for high quality yields. The choice of the type and quantity of fertilizers is determined by nutrient levels of the soil. Hence it is advisable to carry out soil analysis before fertilizer application in potato fields. Poor application of fertilizers may results in poor quality yield. When potatoes are grown under deficient or excessive Nitrogen, harvested tubers are smaller, have higher sugar levels, and lower starch content than desired. Tuber maturation is also affected. Without proper N fertilization, plants are more susceptible to diseases. Excessive N can also delay tuber initiation and promote overgrowth of vines even rotting of tubers
Recommended Basal fertilizer application
Basal fertilizer is applied to potato field before or during planting. Firstly, the ridges are opened for fertilizer application. The depth of opening should be around 12-15 cm. It is strongly recommended to carry out soil test to establish the fertilizer requirement levels of your field. Farmers may consult Agricultural Extension Officers in their area who may guide them on how soil tests for their field may be carried out.
In Malawi for example in the absence of soil test; in most soils, it is recommended to apply NPK 8-18-15 + 6 S commonly called D-compound at the rate of to 400kg/ha (8 bags/ha) where potatoes are grown for seed or rate of 300kg/ha where potatoes are grown for consumption, may be used as basal application. The fertilizer is applied at the rate of about 20 g per metre of ridge length using two cup cupfuls of cup No. 5. The fertilizer is applied in the opened ridge or row. The applied fertilizer is mixed with soil using a stick while taking care not to reduce the opening depth; this operation is done to avoid direct contact between fertilizer and tubers to be placed during planting Farmers may also 23:21:0 +4S fertilizers but this not encouraged because this type does not contain all the required balanced levels of the fertilizer nutrient levels i.e. ‘0’ on the 23:21:0+4S denotes that it does not contain K which is an important element for potato tuberisation process.
Top dressing (Second fertilizer application)
A second dose of nitrogenous fertilizer such as CAN or Urea fertilizer when the crop is 14 to 21 days after planting and plant height is about 15 to 25 cm. However, in tropical regions such as Malawi it is advisable to use CAN than Urea because Urea evaporates or volatilizes when exposed to sun and also encourages more vegetative growth and watery or soft starch tubers that is very susceptible to rotting. Apply the fertilizer in the grooves in the soil surface 5 cm away from stems. Apply about 30 g of the fertilizer using 10 cupfuls of cup No.5 per metre. This mainly applies when the crop is grown for seed. For ware potatoes the grower may apply 20 g per metre of ridge length using 5 cupfuls of cup No. 5. It should be noted that too much fertilizers or too close to the plant can burn the stems and leaves of the potato plant. Also note that nitrogen fertilizer such as Urea evaporates or volatilizes when exposed to sun. This justifies why hilling up (or banking) of plants should be done immediately after second fertilizer application. Adding soil around plants helps tubers and stolons (underground stems that carry tubers) to be kept in the soil. If stolons come out of the soil they will produce stems with leaves instead of tubers. Soil test results may also be necessary to guide the farmer on the quantity of CAN or Urea to apply per hectare of land. Where no soil test exists, 200-250 kg of CAN per hectare may be applied or 150-200 kg of Urea (46%N) per hectare may be applied for potatoes grown for seed whereas 150-200 kg/ha of CAN may be applied to achieve high tuber yield. Nevertheless, it is strongly recommended that for commercial farming soil test be conducted.
The nutrient requirement of potatoes is very high. It has a shallow root system and also a very short growing period during which it must bulk up yield. Nutrients must be readily available in correct and balanced amount. Tuber quality is also significantly affected by plant nutrition. Phosphorus deficiency and Nitrogen or Potassium excesses can decrease specific gravity leading to small tubers hence low yields. Growth disruptions, because of fluctuations in nitrogen supply, can cause misshapen tubers with brown centres or hollow centre. Potassium deficiencies can result in increased black spot bruise at harvesting, darkened colour, and storage problems. Excess Nitrogen, on the other hand, can delay tuberisation and slow skin development at maturity. Vines with excessive nitrogen can create an environment more conducive to infection by certain pathogens. Calcium deficiency has been associated with internal brown spot. The potato plant has a poorly developed root system. Fertiliser is therefore mainly applied in the planting furrows at the time of planting. It should preferably be placed at the same level as, or under, the seed tubers. It is recommended that potato planters be equipped with bins for fertiliser application. If the phosphorus requirement is very high, some of the phosphorus may be broadcast and incorporated into the topsoil. The rest is then applied in the planting furrows along with the nitrogen (N) and potassium (K). Nitrogen top dressings are applied on either side of the plant row, after the rows are ridged and irrigated. Potatoes respond well to fertilizers. Being a root crop, they respond well to phosphorous and nitrogen.