• Sugarcane is a giant crop producing a huge quantity of biomass and therefore its nutrient needs are high. A 12 month crop on an average, produces 45 tonnes of total dry matter per hectare (= 100 tonnes of cane; 10 tonnes of sugar).
• An average of 1.0 kg N, 0.6 kg P₂ O₅ and 2.25 kg K₂O are removed by a tonne of sugarcane. Thus a 100 tonne crop per hectare removes 100,60,225 kg N, P₂ O₅ and K₂O from the soil respectively.

• As already stated, N, P and K requirement of sugarcane is quite large – an average of 100, 60 and 225 kg N, P₂O₅ and K₂O per hectare is actually used up by the crop to produce around 100 tonnes of cane yield. Dosage must be decided based on the crop requirement, contribution from the soils and organic manures applied, likely losses of the applied nutrients by means of fixation, leaching, volatilization etc.

• It is best to follow ‘field – based’ approach to decide about the dosage. This needs information on soil nutrient status, variety to be grown (high yielding or moderate yielding), soil reaction, availability of organic manures etc.
• Soil samples from the field concerned may be drawn and tested through soil testing laboratories of the Agricultural Departments or other reliable agencies and recommendation obtained.

• Nitrogen is the key nutrient element influencing sugarcane yield and quality. It is required for vegetative growth, i.e., tillering, foliage formation, stalk formation, stalk growth (internode formation, internode elongation, increase in stalk girth and weight) and root growth. Since vegetative growth is directly related to yield in sugarcane, the role of nitrogen is paramount to build yield.
• Deficiency of nitrogen causes paleness of foliage, early leaf senescence, thinner and shorter stalk, and longer but thinner roots.
• Excess N is also harmful. It prolongs vegetative growth, delays maturity and ripening, increases reducing sugar content in juice and thus lowering juice purity, and increases soluble N in juice affecting clarification.
• Due to increased succulence the crop becomes susceptible to lodging and pest attack.

• Normal cane development depends greatly on the presence of phosphates in soluble, plant absorbable form in the soil. Phosphorus requirement is relatively less than N and K.
• Phosphorus plays a very significant role in sugarcane production. It stimulates root growth and is required for adequate tillering. It interacts with nitrogen and thus influences ripening.
• Deficiency of phosphorus leads to reduced tillering, delay in canopy closure and thus leads to greater weed infestation. Stalk elongation is also affected.
• Adequate presence of phosphorus in cane juice, about 300-400 ppm, is necessary for proper clarification while processing.

• Pottasium requirement by the crop in general is greater than nitrogen or phosphorus. For sugar synthesis and its translocation to the storage tissue, potassium is highly important.
• Potassium gives resistance to sugarcane against pests and disease attack and lodging. It helps sugarcane under moisture stress by maintaining cell turgidity.
• It has a balancing effect on both nitrogen and phosphorus.

The Quantity of fertilizer to be applied is calculated as follows:

Fertilizer to be applied =Dosage of nutrient to be applied x 100 / % nutrient content in the fertilizer

• Phosphorus should be applied in bands right below the root zone. This could be achieved by applying the phosphatic fertilizer in the furrow bottom before planting sugarcane setts and mixing slightly with soil.
• Nitrogen and potassium fertilizers are given in split doses, applied in bands. An important precaution is to cover the fertilizer soon after application, because under hot weather condition huge loss of nitrogen takes place due to volatilization.
• To cover the fertilizer, partial earthing is done after first top dressing and full earthing up is done after second top dressing.

This is the popular method developed by TNAU getting spread among the farmers.

1. 1. Planting setts obtained from 7-8months old healthy nurseries and planted in paired row planting system     with the spacing of 30x30x30/ 150cm.
2. 2. Nine setts per meter per row have to be planted on either sides of the ridge thus making it as four row     planting system.
3. 3. 12mm drip laterals have to be placed in the middle ridge of each furrow with the lateral spacing of 240cm     & 8 ‘Lph’ clog free drippers should be placed with a spacing of 75cm on the lateral lines. The lateral     length should not exceed more than 30-40cm.
4. 4. Phosphorus @ 62.5 kg ha-1 has to be applied as basal at the time of planting.
5. 5. Nitrogen and Potassium @ 275:112.5kg ha-1 have to be injected into the system as urea and muriate of     potash by using "Ventury" assembly in 10-12 equal splits starting from 15 to 150-180 days after planting.
6. 6. Low or medium in nutrient status soil to be given with 50 percent additional dose of Nitrogen and     Potassium.
7. 7. Irrigation is given once in three days based on the evapo transpiration demand of the crop.

1. 1. Cane yield 175-200 t /ha which is 70-96t/ ha higher than average yield.
2. 2. Saves 25-50 per cent irrigation water.
3. 3. Can either go for additional area under cane cultivation or double the yield with same area with the saved      water.
4. 4. Irrigation water saved and produce more cane per unit of electricity used.
5. 5. Irrigation, fertilizer application, weed management cost reduced considerably.

• Nitrogen requirement of sugarcane is greatest during the tillering and the early grand growth phase. Most of the N uptake by the crop takes place within the first six months.
• During germination external nitrogen supply is not required. Therefore, basal application, i.e., application at planting, is not required in most cases.
• The tillering phase needs nitrogen for tiller formation and growth. Therefore, the first application of nitrogen should be at the start of the tillering phase.
• Crop requirement for nitrogen is higher at the beginning of the grand growth phase or the end of tillering phase. This facilitates cane formation, checks tiller mortality and promotes cane growth. Therefore, second application for an Eksali crop is done at 90 – 120 days period.
• Late application of nitrogen beyond 120 days in a 12 month crop will have adverse effect on juice quality. There will be continued vegetative growth, late tiller formation, reduced pol% juice, increase in soluble nitrogen in juice, water shoot formation and such other problems affecting sugar recovery.
• Potassium applications are usually done along with nitrogen application. This is because of better utilization of nitrogen by the crop in the presence of potassium. Therefore potassium is applied along with nitrogen on 45^th and 90^th day.
• Phosphorus application should be done before planting right below the setts in the root zone. this is because, phosphorus is a highly immobile nutrient unlike N or K. It should be available right near the roots for its effective uptake.
• It gets fixed in the soil quickly and therefore there is limited chance for losses other than fixation. The fixed phosphorus is not lost, but will be available slowly over the period of time.
• Phosphorous need is greater in the formative phase of the crop. Tillering is seriously affected when phosphorus is defecient. Thus the optimum time of soil application of phosphorus is just before planting right below the setts.
• Fertilizer applications should always be followed by irrigation. The time of application should be adjusted to irrigation water availability.
• Irrigations given after fertilizer application should not be excessive, because excess irrigation will leach out considerable quantities of the applied nutrients.
• For early and short duration varieties application of nitrogen and potassium has been found optimum in 3 equal splits on 30, 60 and 90 days.
• Ratoons in general require early application of fertilizers.
• Application of 25 per cent excess N, a fortnight ahead and withholding irrigation during September second fortnight arrests flowering/arrowing in cane without affecting sugar quality.
• Stubble shaving and shoulder breaking, application of 25 per cent additional basal dose of N encourages uniform and better sprouting of sugarcane stubbles.
• Phosphorus needs to be applied as basal dose at planting and N and K need to be applied in three equal splits on 30^th, 60^th and 90^th day of planting in heavy soils (clayey soils) and in four equal splits on 30^th 60^th, 90^th and 120^th day of planting in light textured (sandy) soils.

• Fertilizers are the critical inputs, but are becoming costly. Improvements in their efficient use is important.

• Pocket manuring is an improved method of fertilizer application intended to improve fertilizer use efficiency and check loss of nutrients. Usually top dressing is done through pocket manuring.
• In this method 10cm deep hole is made around 7 cm away from the sugarcane clumps using a sharp stick, and fertilizer is placed in it and then covered by pressing the soil. the pockets could be at 30 – 45 cm spacing.
• To apply one hectare of sugarcane about 8 -10 labourers are required. A simple hand operated tool has been developed by the Mohanur Co-operative Sugar Mills in Tamil Nadu to apply manures by pocket method.

• Neem cake powder is mixed with urea in the proportion 4:1 and then applied to the field. Neem cake and urea are taken in the proportion mentioned in a gunny bag, some quantity of kerosene is added to wet the contents and then they are mixed by swinging to and fro.
• The mixture is then spread in shade and dried overnight and applied on the following day. The neem cake blended urea behaves like a slow-release fertilizer.

• Split applications in small quantities at critical stages of crop growth would help improve fertilizer use efficiency. For early maturing and short duration varieties applications at 30, 60 and 90 days in equal splits is ideal.

• A large proportion of the applied phosphorus gets transformed into unavailable form by combining with other elements. Fixed phosphorus will be available slowly. To reduce phosphorus fixation, correction of soil pH is important.
• Addition of organic matter, green manuring, reclamation of soil by amendments (i.e., gypsum application in high pH soils, addition of lime in acid soils) and crop residue addition will help improve phosphorus availability.
• Application in the root zone is important to overcome the problem of low mobility and for better root growth.

• Frequent light applications are better than heavy single application to check leaching and to avoid luxury consumption and fixation.

• In INM approach, chemical, organic and biological fertilizers/manures are used in suitable combinations, complementing each other and often producing synergistic effect to optimise input use and maximise production and sustain the same without impairing crop quality ,soil health or any other environmental aspects.

Chemical : Fertilizers

Organic: FYM, compost, pressmud, crop residues, byproducts, effluents etc.

Biological : Bio-fertilizers, green manures, leguminous companion and rotational crops, crop rotations.

Soil : Native nutrient available and fixed. Biological fixation by native microbes.

• Optimum dosages of nutrients and combination of sources
• Times of application
• Correct method of application
• Economics, efficient use
• Environmental effects

• Important biological nitrogen fixing agents in sugarcane system are Azospirillum, Azotobacter and Acetobacter. For phosphorus solubilization Phospho bacterin is useful.
• Azospirillum brasilense, the sugarcane N fixing bacteria has been widely tested and proved effective. It can contribute 50 – 75 kg N/ha.
• Azospirillum culture is mixed with powdered FYM, or compost or pressmud and then applied to the base of the sugarcane plant.
• Sufficient soil moisture is essential. Therefore, after application irrigation should follow.
• Azospirillum and chemical fertilizer should not be applied together as chemical fertilizer may affect the activity of the microbes.
• It has been found that Azospirillum is effective under low inorganic fertilizer application levels. Azotobacter has also been found useful for sugarcane.
• Another important biological N fixing is Acetobacter diazotrophicus. It can substantially reduce inorganic N application rates to the extent of 50%. It is referred to as "black urea".

• Several bacteria and fungi are known to solubilize fixed phosphorus and make it available. Bacillus megatherium variety phosphaticum known as ‘phospho bacterin’ has been found to be quite effective.
• This could be applied at 10 kg culture mixture per hectare. It is applied in two doses – around planting to 3 – 4 weeks and then at around 60 – 75 days after planting.
• About 25% saving in phosphorus dosage has been achieved by this.
• The cane yield recorded with the application of 8 kg/ha of phosphobacteria and 60 per cent P₂O₅ as Super phosphate is on par with the yield recorded by the application of 8 kg/ha of phosphobacteria and 100 per cent P₂O₅ as mussorie rock phosphate. Similarly, incorporation of 6 kg/ha Azotobacter with 225 N/ha recorded equal cane yield as that of 275 kg N/ha as urea alone.

• Pressmud is the most important sugar industry by – product useful for sugarcane nutrition. It contains substantial amounts of phosphorus, nitrogen and other nutrient elements.
• It could be composted and used at rates 10 – 15 tonnes per hectare. However, very heavy application may affect soil physical properties.

• Sugar factory effluent water can be used for irrigating sugarcane after proper treatment and dilution with positive effect.

• About 40% of the biomass produced by sugarcane is trash. Sugarcane trash contains about 0.35% N, 0.13% P₂O₅ and 0.65% K₂O.
  Trash can help enrich soil with organic matter and add considerable quantities of the nutrients. Trash can be composted and used for sugarcane.

• Growing green manures like sunnhemp, daincha as intercrops in sugarcane adds 15 t/ha of green manure when incorporated in soil and increase cane yield by 10-15 t/ha.

Details of technology : TNAU Biofert-1 is recommended for sett treatment (2kg/ha) and soil application (2.4kg/ha each at 30,60 and 90 days after planting) as that Azospirilum.

Benefits : Four to 17 percent increased cane yield

Application of 75 per cent of recommended nitrogen with TNAU biofert-1 will increase the cane yield compared to 100 percent N.

Five to 26 percent increase cane yield is obtained due to the new biofertilizer over the Azospirilum.

This new biofertilizer enhances the growth and cane yield and found more suitable for sugarcane than Azospirilum.

Economics : The minimum benefit / cost ratio is 2:1.

• Integration of 210kg N as Neem coated urea + 25t press mud + 10 kg each of Azospirillum and Phosphobacteria/ha recorded higher yield.

• Intensive sugarcane cultivation and inadequate supply of organic matter has led to some micronutrient problems in sugarcane cultivation.

• Application of 100kg of Ferrous sulphate with 12.5 t/ha of farm yard manure/compost basally or spray of 5kg of ferrous sulphate+2.5kg urea in 500 litres of water/ ha on the foliage, 2 to 3 times at 7 to 10 days interval helps to manage iron chlorosis.
• Occurrence of Iron deficiency (Iron chlorosis) in iron deficient soils/ratoon sugarcane having stresses could be corrected by spraying of 5 kg Ferrous sulphate + 5 kg Urea dissolved in 500 litres of water per hectare of 15 days interval till deficiency symptoms disappear.

• Zinc is a necessary component of many enzymes systems regulating metabolic activities.
• The deficiency symptoms include shortening of internodes, chlorotic young tillers and necrotic leaves from tip downwards. Veinal chlorosis and cessation of growth of terminal bud takes place in acute conditions.
• Soil application of zinc sulphate at 50kg/ ha or spraying 0.5 per cent ( 5 gm / litre) at 15 days interval for four times rectifies the deficiency.

• Copper plays an important role in protein and chlorophyll synthesis and oxidation-reduction processes. In salt affected soils, copper uptake is prevented.
• The deficiency symptoms are droopy top, failure of spindle to unroll and softness of stalk. To correct copper deficiency, 10kg of copper sulphate/ha may be applied.

• Boron aids in sucrose translocation, improves tillering and juice quality.
• Deficiency leads to distortion of growing spindle, curling of leaves and minute spindle-shaped watery spots in young leaves.
• Borax spray at 0.02 gram per litre corrects deficiency problem.

• It aids in certain oxidation process in plant metabolism, development of meristematic tissues as well as synthesis and breakdown of proteins through increased enzyme activity.
• The symptoms of manganese deficiency are similar to iron. The chlorotic stripes rarely extend over the entire length of leaf.
• Soil application of manganese sulphate at 4 kg /ha or foliar application of 0.25 to 0.5 per cent at weekly intervals rectifies the deficiency.

• Sulphur plays an important role in the formation of chlorophyll. Sulphur deficiency symptoms are similar to those of nitrogen deficiency at early stages.
• Later on differentiated by light purplish tinge in the light yellow-green colour. The leaves become narrow and shorter in length, stalks with shortened internodes.
• Superphosphate application itself can meet the sulphur requirement since it contains 12 per cent sulphur.