Managing Plant Nutrients When Both Manure And Fertilizer Applications Are Used

There are three main sources of plant nutrients available to farmers. They are commercial fertilizers, livestock manure and municipal sewage sludge or biosolids. There is a preconceived notion that a farmer will only use one of these sources to supplement nutrients supplied by soils. However, these sources can be used in combinations very successfully.

When considering the weight of material applied to soil, manures are the greatest, followed by fertilizers, and lastly biosolids. However, the actual amount of nutrients supplied with fertilizer is still highest because of their greater concentrations compared to organic sources. Typical liquid dairy manure has a fertilizer analysis of 0.4% N, 0.2% P2O5, and 0.5% K2O.

A typical fertilizer NPK fertilizer blend, used for a small grain crop, would have a blend analysis of 22-9-18 — or about 50 times greater concentrations of plant nutrients compared to liquid dairy manure. Fertilizers are much less expensive to transport compared to manure in order to supply the equal amounts of nutrients to a field. For this reason, the amount of nutrients supplied annually in the U.S. through fertilizer is 20 times greater compared to that applied as biosolids and manure combined. Plus, only a small percentage of cropland receives manure. In Canada, only about 4% of cropland receives manure applications compared to 96% that only receives fertilizer. This excludes some organic crop production land that receives neither manure nor fertilizer.

One disadvantage of only using manure compared to a combination of manure along with additional fertilizer is that the balance of nutrients can be less than ideal. For example, a barley crop yielding 100 bu/A (5,300 kg/ha) will take (per acre) 100 lb N, 42 lb P2O5, and 33 lb K2O from the soil. This equates to a N: P2O5: K2O use ratio of 2.7: 1: 0.8, which translates into a higher N requirement than can be supplied from typical manures. To better supply N, P and K to a barley crop, a farmer could apply additional N fertilizer along with manure to more closely approach the actual nutrient use ratio of the crop.

What can work well for farmers is to apply manure once every three years. In the year of application, manure is applied at a rate to supply the N requirements of the crop and excess P and K is supplied. For the next two years, only N fertilizer is required as residual P and K from the manure usually satisfies crop demand. Additional low rates of P and K might be used as seed-row starter fertilizer to get crops off to a good start under cool spring soil conditions. This approach works well to grow adequate yields while avoiding excess build up of soil P and K.

It is recommended that soil nutrient content be monitored annually or at least every three years, by having representative soil samples analyzed, and the results interpreted by a qualified consulting agronomist, or certified crop adviser. How often manure can be applied and what rates of fertilizer nutrients are required each year will need to be adjusted depending on the crop to be grown, crop yields, nutrient removal in harvested grain or forage, the manure type and its nutrient content and weather conditions. By using a combination of manure and fertilizer applications, crop nutritional needs can be met while avoiding excess levels of nutrients in your soil.

Source: IPNI Plant Nutrition Today

Leave a Reply

Crop Inputs Stories

Soybean field
FungicidesValent Launches New Seed Protection Fungicide For Soybeans
July 16, 2014
The INTEGO SUITE System contains the first new, novel seed protection fungicide chemistry registered in 30 years by the EPA for protection against Pythium and Phytophthora. Read More
InsecticidesEPA Grants Besiege Insecticide Additional Approvals
June 18, 2014
EPA has granted additional registration approvals for the use of Syngenta's Besiege insecticide on sorghum, cereal grains and peanuts. Read More
HerbicidesArysta Touts Burndown Herbicide For Brome Management In Wheat
June 4, 2014
Arysta LifeScience North America recommends PRE-PARE Burndown Herbicide for effective brome management in winter wheat. Read More
HerbicidesFall Herbicide Applications More Effectively Manage Resistant Italian Ryegrass
May 14, 2014
Field studies show that a fall application of certain herbicides before weed emergence, leads to more successful crop planting and weed control in spring. Read More

Trending Articles

Retail FacilitiesWaconia Manufacturing Builds Facility Designed For Speed, Efficiency
July 7, 2014
To make its new hub facility more efficient, Cooperative Elevator enlisted the aid of Waconia Manufacturing. Read More
EquipmentSummer Show Preview 2014: Superior Sprayers Take The Field
July 3, 2014
In this final installment of our coverage of the major categories of Big IRON that retailers can expect to test-drive at this summer’s events, here is a look at 19 sprayers. Read More
Scouting a soybean patch at Green Valley Ag.
EmployeesCropLife Compensation Survey: Battling Talent Drain
July 2, 2014
Retailers too often lose employees to companies outside of agriculture, while recruiting efforts are most often limited to competitors and other ag-focused organizations. Read More
HerbicidesDow AgroSciences Introduces SureStart II Herbicide
June 16, 2014
The enhanced formulation has improved viscosity and increased stability under heat and controls more than 60 high-anxiety grasses and broadleaf weeds found in corn fields. Read More
HerbicidesBASF Investing $270 Million To Expand U.S. Herbicide Production
June 11, 2014
BASF has invested more than $270 million to expand herbicide production capacities in the U.S., including more than 20 new products to be launched over next two years. Read More
EquipmentGPS: 25 Years And Still Growing
June 2, 2014
The evolution of global positioning systems applications in agriculture remains ongoing as the technology hits a notable milestone. Read More

Latest News

CropLife 100Pinnacle Forms Alliance With Wildlife Managment, Seed O…
July 25, 2014
The strategic alliance will provide Tecomate with key wildlife products, processing facilities, distribution centers and sales through Pinnacle’s ever-growing retail network. Read More
ManagementFranken Presses White House On RFS Support
July 25, 2014
Al Franken and a group of Senate democrats recently met with senior White House official John Podesta to urge the administration to change its position on an EPA proposal. Read More
ManagementASA, FarmLink To Launch ‘Operation Benchmark̵…
July 25, 2014
The American Soybean Association (ASA) and FarmLink are teaming up to help farmers close the $11 billion gap between what they harvested in 2013 and what they could harvest annually. Read More
StewardshipNorthey: Farmers Commit $1.4 Million to Try New Water Q…
July 25, 2014
The practices that are eligible for funding include cover crops, no-till or strip till and using a nitrification inhibitor when applying fall fertilizer. Read More
Precision AgFarmers Learn How Changing World Will Impact Iowa
July 24, 2014
Technology and understanding global consumer demand for Iowa farm products brought hundreds of farmers and agribusiness leaders to Ames recently for the annual Iowa Farm Bureau Federation Economic Summit. Read More
HerbicidesPurdue: Late Season Weeds May Require Manual Removal
July 24, 2014
Hand-rouging and pulling late season weeds by hand may be the best way to remove them, more so than using a herbicide, a Purdue Extension weed scientist says. Read More
Soybean Field
InsecticidesTransform WG, Closer SC Insecticides Receive R&D 10…
July 23, 2014
Dow AgroSciences has received the award from R&D Magazine for Transform WG insecticide and Closer SC insecticide with Isoclast active. Read More
EquipmentKinze, Raven Team Up On 4900 Planter Monitor
July 23, 2014
Kinze Manufacturing announces a partnership with Raven Industries to develop a standalone monitor solution for the Kinze 4900 series planter. With this new Read More
LegislationNew Farm Bill Continues To Confuse As Growers Await USD…
July 23, 2014
The new five-year Farm Bill eliminates many of the direct payments previously payed to growers and could benefit from USDA clarification, reports a Toledo Blade columnist. Read More
EquipmentPrecisionAg.com Relaunches With Responsive Design For M…
July 22, 2014
PrecisionAg, the worldwide leader in precision agriculture information and analysis, announces the launch of its completely redesigned website, PrecisionAg.com. Read More
FungicidesEPA OKs Two Willowood Fungicides
July 21, 2014
The EPA has approved Willowood Azoxy 2SC and Willowood AzoxyProp Xtra. two widely used broad spectrum, preventative fungicides with systemic and curative properties. Read More
Precision AgFarmers Learning Fast As UAVs Take Off
July 17, 2014
Farmers and others interested in how UAVs can be used in agricultural applications were able to learn more about the technology during the recent Precision Aerial Ag Show. Read More
CropLife 100Bobby Knight, Richard Petty To Highlight Ag PhD Field D…
July 17, 2014
Attendees at the July 24 Ag PhD Field Day at Hefty Farms will learn about the latest agricultural technologies, and get a chance to meet legendary sports figures Bobby Knight and Richard Petty. Read More
WebinarsUpcoming Webinars
July 17, 2014
Register for one of our upcoming Webinars or access our archive of past Webinars to view recordings of presentations that may be of interest to you. Read More
A finished Willmar 16-ton side-shooting tender.
TendersNew Production Facility Helps Willmar
July 17, 2014
In 1963, a group of businessmen started Willmar. Today, a half-century later, the company is one of the ag industry’s longest-running brands. Read More
FertilizerCF Industries Sells Carbon Credits To Chevrolet, Donate…
July 17, 2014
CF Industries has completed the sale of a large block of carbon reduction credits to Chevrolet, and will donate the net proceeds of $600,000 to the National FFA Foundation. Read More
CropLife 100Grainland Cooperative, Minier Cooperative Grain To Merg…
July 17, 2014
The shareholders of Grainland Cooperative and Minier Cooperative Grain Co. approved a merger of company operations effective August 1, 2014. Read More
ManagementStudy: Drought Costing California Billions
July 17, 2014
A new study has found the drought has cost the state $2.2 billion, primarily in lost farm revenue and wages. Read More