Rice:Foliar Fertilizers

INTRODUCTION:

• In recent years soluble fertilizers otherwise known as foliar fertilizers were introduced in A.P in the names of Polyfeed and Multi ‘K’
• Polyfeed contains 19 : 19 : 19 NPK with 6 micro-nutrients like iron, manganese, boron, zinc, copper and molybdenum, while multi K contains 13 : 0: 46 NPK.
• These fertilizers provide nutrients to the plant by foliar application as these fertilizers are completely soluble in water.
• These fertilizers have no other impurities like sodium and chloride and they are 100 % nutrients and these nutrients are easily absorbed through the leaves.
• In certain occasions like prolonged drought, there is no scope to apply fertilizers to the soil for want of moisture. Like wise in flooded conditions due to continuous rains fertilizers could not be applied to the soil.
• In such special circumstances these soluble fertilizers are must to protect the crop against hunger and this forms a compulsory act of crisis management.
• And the foliar application of Speciality fertilizers play an important role in supplying the nutrients at critical stages of flowering and fruit development.
• The experiments conducted in different countries indicated that these soluble fertilizers as supplement to soil application of fertilizers enhances the production per unit area ranging from15-25%.
• The trials conducted in Andhra Pradesh and Tamilnadu also indicated that the use of Speciality fertilizers enhance the yields in several crops like Paddy by 10%, Pulses, Chillies, Cotton, Groundnut by 20% and Cashew and mango by 20%

Types of Fertilizers

1) Multi - K 13% Nitrogen and 46% K
2) Polyfeed 19:19:19 N: P:K and 6 micronutrients

• These Speciality fertilizers are to be applied at the recommended concentrations. These fertilizers are compatable with insecticides and fungicides except sulphur

	Speciality Fertilizers	Other Fertilizers
Solubility	Fully water soluble. Dissolves rapidly in water and remains in solution without impurities,(detrimental chloride and sulphate).	Not water soluble and leaves soluble deposits with impurities except urea.
Absorption	Plant nutrients are ionic form(chelated) and available for plant absorption. Multi'K' K= (K) and N = ( No3) Polyfeed N= (No3)NH4) and P=(Po4) K =(K+) and Fe, Mn, B , Zn, Cu, Mo in PPm	Mostly in oxidized salt form. MOP in K2O,SOP in K2O, CSP in P2O5, N fertilizers mostly in salt conditions except urea.
Activity	Plays vital role in plant metabolic activities and also plant food.	Utilized as plant nutrient (food)
Yield	Exploit fully yield potential in quality and quantity by increasing 15 - 20% Yield at suggested dosage 1% - 2% spray	Increased yield if applied in balanced ratio a( proportion) NPK ( 4 : 2 : 1)

Application

• Application is suggested at different critical plant stages as nutritional foliar spray and fertilization. Eg: Before reproductive stage and after grain setting @1% spray of multi K.

Results

• The experiments conducted at NARDI indicated that foliar spray of 1 % either polyfeed or Multi ‘K’ at 45, 60 and 75 days after planting increased the rice yield by about 10 % over unsprayed control. Observation trials conducted by KVK (NFCL) indicated that foliar application of Multi ‘K’ at 1 % at the time of maximum tillering and prior to panicle initiation resulted in increased yield of 16.8 % over untreated control.

Fertilizer recovery

• Recovery of top dressed fertilizer varies throughout the life cycle (mainly as a function of root growth)
• In terms of N recovered from fertilizer N applied (%)
  • Basal 15-30
  • At midtillering 30-50
  • At panicle initiation 45-75
  • At flowering 35-60

Phosphorous and Potassium

• P and K are typically applied as basal application , although application at 10 DAS in direct sown crops may improve the recovery efficiency of P applied from 20-35%.
• K can also be splitted and the splitted 50% K at basal and 50% at PI but this is mainly to improve pest resistance.

• Benfits of Polyfeed

• Readily taken up by plants, correct deficiencies of both macro and micro nutrients.
• Immediately increases grain size.
• Improved protein content in grains.
• Efficient utilization of all nutrients.

Multi - K

1. Efficient utilization of nutrient in the plant.
2. Induces panicle initiation.
3. Induces resistance from pests and diseases.
4. Imparts drought and lodging resistance
5. Improved protein content in grains.
6. Improves crop quality.