Agronomic Services — News ReleaseFOR IMMEDIATE RELEASE
TUESDAY, OCT. 25, 2005
|Contact:||Catherine Stokes, information and communication specialist
NCDA&CS Agronomic Division
New peanut grower faces challenges
BUNN LEVEL — This year Jeff Autry did something that had not been done in Harnett County in more than 60 years —he grew peanuts. Autry, who grew 300 acre of peanuts, learned a lot from the experience and hopes his findings will be useful for other new peanut growers.
"I grow cotton and tobacco primarily," Autry said. "I decided to grow peanuts because it offers more potential return than cotton and also because it's a good crop to rotate with cotton. It hasn't been a real good year to start, though, because it's been so dry."
Now that peanut quotas are no longer in effect, many N.C. farmers are planting the crop for the first time, and often on land where it has never been grown. Like Autry, these growers may be discovering that peanuts have some unique fertility issues, particularly with respect to calcium, potassium and zinc.
Don Nicholson, a regional agronomist with the N.C. Department of Agriculture and Consumer Services, helped Autry investigate and manage nutrient problems during the growing season. "There are several factors to consider when starting out with peanuts," Nicholson said. "You've got to consider the crops that were grown previously in a field, how they were fertilized and what pesticides were used."
In Autry's case, some of his peanuts were planted after tobacco and some followed cotton. A unique set of problems developed in both due to the fertilization of the previous crop. Peanuts following tobacco needed extra calcium, and some of the peanuts following cotton showed signs of zinc toxicity. Peanuts planted after tobacco are likely to need additional calcium because fields where tobacco has been grown are often high in potassium from fertilizer use. High levels of soil potassium, however, can interfere with plant uptake of calcium. In peanuts, insufficient calcium increases the incidence of "pops," or empty shells without nuts.
Gypsum (calcium sulfate) is often recommended as a source of calcium for peanuts. Autry, however, used recycled wallboard waste product. It was abundant, locally available and more reasonably priced than gypsum. So far, he has been able to meet his crop's calcium needs with this material.
The zinc toxicity that developed in the peanuts that followed cotton was also directly related to previous fertilization practices. "The land I farm is sandy land, rolling land—bottom of the barrel with regard to fertility," Autry said. "When I first started growing cotton, I put out a lot of poultry litter. On my soils, litter will make good cotton."
Unfortunately, soil that has been amended with poultry litter is not particularly suited to growing peanuts. Litter tends to contain high levels of zinc.
Although zinc is an essential nutrient, plants need it in very small amounts. Very high levels can be toxic. Peanuts are especially sensitive to zinc and can be damaged by levels that will not harm most crops.
"Jeff is a good steward of the land," Nicholoson said. "Every farm I've seen him work is better after he deals with it. There's nobody better in the county.
However, several years ago, it would have been difficult to foresee growing peanuts in these fields."
NCDA&CS soil test reports indicated zinc-index (Zn-I) levels ranging from 159 to 317 in some of Autry's peanut fields. Peanuts often show signs of toxicity when Zn-I values are around 250 or more, especially if the soil pH is not maintained at 6.0. "Hot spots" of dead peanuts did occur in some of Autry's fields.
"Because zinc tends to accumulate in soil, toxicity is a long-term problem," Nicholson said. "Deep cultivation is one way to deal with it. Turning and mixing the soil can reduce zinc levels in the root zone.”
Autry uses conservation tillage practices to prevent erosion and improve soil quality so, in this case, cultivation was not an option. For him, avoiding fields that test high in zinc is the best course. He is already considering the kinds of changes he wants to make.
"I routinely soil sample every three years and use plant tissue analysis and nematode assay as needed,” Autry said. “I would advise anyone starting out with peanuts to pay close attention to cropping history and soil nutrients, to get reliable agricultural advice, and to use agronomic testing services to their advantage."
North Carolinians have access to one of the most comprehensive agronomic testing and advisory services in the nation. The laboratories of the NCDA&CS Agronomic Division measure nutrient levels within soil and plant tissue, identify plant-parasitic nematodes, analyze the nutrient content of waste materials to be used as fertilizer, and test water and nutrient solutions for nutrient content and other chemical properties relevant to plant growth.
To support these testing services, 13 regional agronomists are available throughout the state to visit growers; evaluate suspected nutrient problems; give advice on sampling, liming, fertilization and waste management; and help identify and manage nematode problems. Visit the Agronomic Division’s Field Services Section online at www.ncagr.com/agronomi/rahome.htm to find contact information for the NCDA&CS regional agronomist assigned to your area.
Agronomist Don Nicholson is available to provide advice on fertilization, nutrient management or nematode problems in Harnett, Johnston, Wake, Wayne and Wilson counties. He can be reached by phone at (919) 498-0504 or by e-mail at firstname.lastname@example.org.