FERTILIZER RECOMMENDATIONS – 2011

NITROGEN (N)

Crop Soil Type Nitrogen Rate

(lbs N/acre)

Plant-cane Light 60 – 80

Plant-cane Heavy 80 – 100

Stubble Light 80 – 100

Stubble Heavy 100 - 120

 For efficient nitrogen utilization, it is important that soil pH is in balance (ideally 6.2) and 

adequate P & K are available.

 Recommendations are based on tests where UAN 32% was the primary nitrogen source.

 Recommendations are based on data with current varieties and on a wide range of soil 

types at locations throughout the industry on plant-cane through third stubble crops.

 Higher than recommended rates of nitrogen may increase tons of cane per acre, but also 

decrease sugar per ton of cane. Recommended rates will maximize sugar per acre yields 

with optimum sugar per ton of cane.

 Apply nitrogen between April 1 and April 30. 

 There is an association between rust severity and excess levels of nitrogen.
POTASSIUM (as K2O)

Soil test category Plant-cane Stubble-cane

----------------------lbs/acre------------------------

Very low 120 140

Low 110 120

Medium 80 80

High 0 0

Very high 0 0

 Recommendations are based on soil tests.

 When prices are high consider applying only when soil test levels are low or very low. 

Although not specifically recommended above, if one is not considering the application 

of potassium at all, it would be wise to consider applying at least 60 lbs/acre to those 

fields testing very low or low.

 Sugarcane utilizes approximately 3 lbs of K2O per ton of cane.

 Response is more likely in a stubble crop than in a plant-cane crop.

PHOSPHOROUS (as P205)

Soil test category Plant-cane Stubble-cane

----------------------lbs/acre------------------------

Very low 50 60

Low 45 50

Medium 40 40

High 0 0

Very high 0 0

 Recommendations are based on results of soil tests.

 When prices are high consider applying only when soil test levels are low or very low.

 Sugarcane utilizes approximately 1 lb of P2O5 per ton of cane with availability dependent 

upon soil pH & soil type. Optimal soil pH for best phosphorous availability is 6.2.

 There is an association between rust severity and excess levels of phosphorous.
SULFUR (S)

Soil test category Plant-cane Stubble-cane

----------------------lbs/acre------------------------

Low 24 24

High 0 0

 Recommendations are based on results of soil tests.

 Stubble cane is more likely to respond than plant-cane.

 Response is more likely on medium-heavy to heavy textured soils.

 There is an association between rust severity and excess levels of sulfur.

MICRONUTRIENTS

Zinc (Zn)

Soil test category Application Rate

-------lbs/acre----------

Very low (<1 ppm) 6

Low (< 2.25 ppm) 3

 Apply only if soil tests or tissue analyses indicate deficiencies.
LIME

Check lime requirements by conducting soil tests. Liming is primarily a method of correcting 

soil pH, but there are several other benefits to include:

 To adjust soil pH to improve fertilizer use efficiency by maximizing nutrient availability.

 To supply calcium, an essential plant food nutrient. If magnesium is deficient, use 

dolomitic limestone.

 To reduce aluminum and manganese toxicity.

 To enhance the activity of soil microorganisms.

 To improve the activity of soil applied herbicides.

 To decrease the total amount of lime applied, consider variable rate lime applications.

Lime when:

 Soil pH <5.8 on sandy loam & silt loam soils.

 Soil pH <5.2 on clay loam & clay soils.

 The lime rate should be based on soil test and ideally should raise soil pH to 6.2.

 It is ideal to broadcast lime to fallow fields or in crop during the fall or winter.

 Apply lime after precision leveling.

How Long Will it Take for Lime to Work?

 The biggest change in pH will occur within 3-4 months. The pH may continue to 

increase for 6-12 months.

1 Prepared by Dr. Kenneth Gravois, Sugarcane Specialist, LSU AgCenter, from information 

obtained from research conducted by Drs. Benjamin L. Legendre, Brenda Tubana, Sonny Viator, 

Jim Wang and Jeff Hoy, LSU AgCenter; and Drs. Rich Johnson, Ryan Viator, Paul White, Mike 

Grisham and Edward Richard, Jr., USDA-ARS, Sugarcane Research Laboratory, in cooperation 

with County Agents, Louisiana Cooperative Extension Service.