BMPs for growing profitability

Vegetable growers struggling with tight profit margins need to use fertilizers in the most efficient manner possible. This not only makes good economic sense, it’s a regulatory requirement to ensure clean water and a healthier environment.

There are a number of ways produce growers can maximize their fertilizer program, comply with the auspices of regulatory requirements – most notably the Federal Clean Water Act (FCWA) – and increase the profitability of their farming operation. Topping that list is a phrase uttered quite often in business circles: best management practices, or BMP.

Much can be learned from the Florida Department of Agriculture and Consumer Services BMP manual, which includes the following advice for vegetable growers: 1) educating and training field operators about how to manage fertilizer, 2) developing a nutrient management plan, 3)using appropriate fertilizer sources and formulations, 4) using application equipment that applies fertilizer to target sites, 5) properly calibrating and maintaining application equipment, 6) using precision nutrient application where appropriate, 7) avoiding high-risk fertilizer applications whenever possible, and 8) using soil moisture sensors to improve irrigation scheduling.

Once these practices become second nature, it’s time to move on to specific practices, technologies, and products that help to maximize a vegetable crop fertilization program.
 

Soil testing

One BMP that should be added to the list is regular soil tests. To maximize a fertilization program and eliminate waste that can potentially pollute underground aquifers, it is important to test the soil regularly, according to Jim Faust, associate professor at Clemson.

“Regular testing of pH and soluble salts is a good crop management tool that can be performed by the grower,” says Faust.

Regular pH testing is important because proper soil pH will maximize nutrient uptake. Vegetables generally grow best in a soil that is slightly acidic, i.e. 6.5. However, if you’re growing a single crop, it is best to check the pH range for the particular crop and adjust your pH accordingly. There are several large universities across the country, and some private companies that do soil tests for a reasonable fee. Included in these tests are fertilizer recommendations for specific crops and any need for the addition of lime or sulfur to correct any pH issues.

With the large appetite most vegetable plants have for nutrients it doesn’t take long for a soil to be depleted of essential elements for a healthy crop. However, in many cases certain major and minor nutrients may already be present in the soil; the addition of more fertilizer will therefore be wasteful.

According to the University of California Cooperative Extension, fields that have been farmed for several years may be able to go without an application of phosphorous and potassium for a couple of years, except perhaps for a small amount of ammoniated high-phosphate starter at planting. A soil test will keep the pulse of your soil in terms of nutrient content and the need to add or not add more fertilizer.
 

Water-soluble fertilizer

Water-soluble fertilizer is relatively inexpensive and can add a quick dose of nutrients to a crop. However, it also leaches through the soil quite readily, particularly sandy soils, potentially resulting in a less than efficient fertilizer program and the contamination of underground aquifers.

BMPs for water-soluble fertilizers include the proper application timing and placement of the product. For example, cabbage is commonly fertilized with a total of 90 to 200 pounds of nitrogen per acre in one to three side dressings before heading starts. Sidedressing after heading begins may result in less solid heads and slower growth, and of course a waste of money. Other BMP for water-soluble fertilizer include adding organic soil amendments that can result in better retention of fertilizer in the root zone and fertigation, which delivers the right amount of water and fertilizer at the right time for the specific crop.

Knowing the minor nutrients needed for good plant growth also will help maximize the efficiency of a fertilizer program. For instance, the symptoms of a lack of iron are similar to the lack of nitrogen, i.e., the yellowing of plant foliage, a.k.a. chlorosis. Not recognizing an iron deficiency via a soil test could result in the overuse of nitrogen to correct a problem brought on by the absence of this important minor nutrient. Other minor nutrients recommended for vegetable crop production are boron, chlorine, copper, manganese, molybdenum, nickel, and zinc.
 

Organic options

Organic farmers and gardeners have known for a long time that enhancing their soil through organic practices will encourage beneficial microbes.

This will, in turn, support good plant growth in vegetable crops, resulting in less fertilizer inputs. A surefire way to improve the efficiency of a fertilizer program is to improve the soil and its ability to utilize nutrients. This can be done with a regular program that incorporaties organic amendments, such as compost and well-rotted manure,into the soil.

Unlike water-soluble fertilizers that readily leach nitrates into the soil, organic products generally stay in the upper layer of the soil and in most cases enhance the soil.

Such poducts may be oilseed-based, offering growers sustainably produced fertilzero options that benefit the environment while enhancing the soil.

Furthermore, low-salt formulations provide a source of carbon to encourage beneficial soil microbe populations.

Other manure-based products in pellet form have been around for decades and remain popular with with vegetable growers.

Keep it simple

For many growers achieving a more efficient fertilizer program is simply a matter of practicing a few common sense principles, including regular soil tests, and perhaps experimentatioin with some new products that are good for plants and the environment.

Neil Moran is a horticulturist and freelance writer based in Sault Ste. Marie, Mich.

Resources
University of Minnesota Soil Testing Laboratory
http://soiltest.cfans.umn.edu/

Michigan State University Soil Plant Nutrients Lab
www.spnl.msu.edu/FieldCropSoilSampleSubmission.htm

Private Soil Testing Labs in Nevada
http://bit.ly/1nigv6Y

BMPs: Florida Department of Agriculture and Consumer Services
http://bit.ly/1q20y8k

pH preferences for fruit and vegetable crops
http://bit.ly/1xZ5F9q

Guide to fertilizing specific crops: University of California Cooperative Extension UC Small Farm Program 
http://bit.ly/1juuWpi