Rice Farming

Dr. Fred Turner once had lofty ambitions for the future of alternative fertilizers in rice production.

“What I originally hoped to accomplish when I began working with sludges was to have a product that they would pay farmers to take instead of paying to take it to a landfill,” says Turner, professor of soils and plant nutrition at Texas A&M University in Beaumont, Texas. “That hasn’t happened yet, and farmers are paying for it.”

Even so, many farmers are finding that sludge, poultry litter and other non-synthetic fertilizers are helping boost production and reduce input costs.

“Alternative fertilizers are something to consider,” Turner says. “There are certain situations where they have some advantages. They are clean materials that are not toxic to the environment. Putting it in the soil instead of the landfill is a good way to manage nutrients and waste products that can benefit everyone.”

Broad definition
The first thing to understand about alternative fertilizers is that the term can encompass a wide range of materials.

“In some contexts, it could mean any fertilizer, natural or synthetic, that is not commonly used by farmers growing a particular crop,” says Dr. Stuart Pettygrove, Extension soils specialist at the University of California, Davis. “In another instance it could be restricted in meaning to ‘natural’ or ‘organic’ fertilizers.”

Organic farmers, for example, typically apply animal manure, green manure or both, he says. Green manure is simply a legume cover crop that captures atmospheric nitrogen and leaves it in the soil for the next rice crop.

“It is difficult to say what an ‘alternative fertilizer’ is,” Pettygrove says, “but I suppose you could say that for conventional rice farming in the United Sates, municipal biosolids, animal manure and other so-called waste products would qualify as alternative fertilizers.”

The use of alternative fertilizers on conventional rice is far from widespread. “I have not kept up on use of alternative fertilizers, but I think usage is quite small in California rice culture,” Pettygrove says.

The same holds true in the Mississippi Delta, says Dr. Timothy W. Walker, Mississippi State University assistant agronomist in Stoneville, Miss.

“Alternative fertilizers at the most would contribute to less than 1 percent of the total fertilizer used for rice production in Mississippi,” he says. “Poultry litter (pelletized or liquid formulations) and Unity (an ammonium sulfate-like product made with sewage sludge) would be the most commonly used alternative fertilizer sources.”

Agronomists typically recommend alternative fertilizers as a supplement to—not a replacement for—conventional fertilizers. They can work well in specific situations, such as cuts in recently graded fields.

Counting the costs
Despite the environmental benefits, the challenge is to make the economics work.

“Growers try out alternative fertilizers in the hope of improved efficiency (i.e., the plant capturing more of the applied nutrient) and, therefore, reducing the amount of nutrient that must be purchased,” Pettygrove says. “Or they may be looking for a beneficial side effect, such as fewer weeds and plant diseases.

“Conventional materials are almost always the least expensive per unit of available nutrient. Less-concentrated fertilizers such as manures, biosolids and chicken litter pellets lead to higher application costs and, possibly, less-uniform application.”

The bottom line must balance environmental impact aginst costs.

“Rice farmers select fertilizing materials almost exclusively based on yield impact and cost,” Pettygrove says. “Recycling of waste products (manure or biosolids) to rice crop land may be an environmentally sound alternative to disposing of them in landfills or on vegetable cropland.

“For the manures and biosolids, the benefit could be (but must be proven) a longer-lasting effect of some of its nutrients, especially N, P, Fe and Zn, compared to inorganic sources of these nutrients. This benefit, when it occurs, is due mainly to the organic matter in these materials.”

However, simple logistics can quickly erase the potential benefits of alternative sources of fertilizers.

“Poultry production is located in the east-central part of Mississippi, which makes it difficult to transport to the Delta,” Walker says. “If transportation were not a factor, poultry litter would be a good soil amendment on precision-leveled soils with some nutrient benefits as well.

“In addition, it would help poultry producers discard this byproduct, which has environmental implications for poultry producers. But the economics of transporting poultry litter to the Delta are not feasible.”

Finally, factor in the amount of alternative fertilizer required to make a crop. “Those who are interested in placing alternative fertilizer products on the market must understand the amount of nitrogen needed to grow a crop,” Walker says. “In Mississippi, approximately 180 pounds of actual N is needed to produce the crop. Low-analysis products just do not fit our production practices.”

Before you buy ‘alternative’ fertilizers, ask these questions:

What is the composition? “When you apply chicken litter, you are never sure if it is 2 percent nitrogen or 5 percent nitrogen,” says Dr. Fred Turner with Texas A&M University.

Don’t be afraid to ask for documentation, adds Dr. Tim Walker, with Mississippi State University. “Any fertilizer or soil amendment must be tested by the Mississippi State Chemical Laboratory before being sold,” he says. “This reduces the risk of producers buying products that do not have a guaranteed analysis.”

How will it be applied? “The method of application is critical for any alternative fertilizer or soil amendment,” Walker says. “If the product cannot be distributed uniformly with commonly used application equipment (sprayers or spreaders), chances are it will not fit into a production setting.”

The economics of application favor conventional products.

“One thing that is unique to rice production is that a lot of fertilizer is still applied with an airplane,” he says. “Airplane costs are based on pounds of product applied; hence, the higher grade the material, the less expensive for application, and vice versa.”

How will it perform in my operation? “All farmers should consider testing materials on a small part of their acreage as part of their ongoing research,” says Dr. Stuart Pettygrove with the University of California, Davis. “However, many farmers find it too time-consuming and costly to do this.

“To get a true picture, replicated strips or plots are required, and the test must be run over several years. Yield monitors on rice harvesters have created a new, less-expensive method for carrying out on-farm trials without having to obtain a small-plot harvester and weigh wagon.”

What is the availability? “Look at accessibility and availability,” Turner says. “Everybody wants fertilizer right before they plant. Will it be available when you need it?”

Does it sound too good to be true? “Does the advertising for the product rely on scientific-sounding mumbo jumbo?” Pettygrove says. “References to enzymes, humic substances or vitamins should raise a caution flag. Don’t forget to check with your Extension agent or farm advisor.”

In the final analysis, the acceptance of alternative fertilizers, as is the case with most inputs, comes down to price and performance.

“If alternative fertilizers can compete with the prices that we have with synthetic products and can be applied uniformly without expensive equipment modifications,” Walker says, “then the use may expand.”

Biosolids make the grade for Texas producer

Leveling rice fields solves one problem while creating another.

“You lose all of your topsoil and its nutrients,” says Dr. Fred Turner, professor of soils and plant nutrition at Texas A&M University. “It is impossible to make maximum yields without adding organic matter after leveling land.”

Des Woods, who farms in the Katy area of Texas near Houston, has found a cost-effective solution by applying municipal waste. The waste, a 6-2-0 fertilizer, is called Vital-Cycle.

“We use it where we do laser work and have cut areas where we need to bring the fertility back,” he says. “It costs $32 an acre applied.”

Vital-Cycle comes from site-specific plants in Houston that receive only residential and restaurant waste, which reduces the problem of high heavy metal concentration found in industrial waste products. Pathogens are eliminated by a multi-step process that begins with microbial decay and ends with the material being heated to 1,200 degrees to eliminate any remaining micro-organisms.

In a recent 18-month study, scientists at the University of Arizona documented that Staphylococcus aureus, a human disease pathogen, is not present in processed biosolids.

Woods makes these observations from his four years of experience with biosolids:

• On rich, healthy soils, cut areas benefit from an application of 1,000 to 2,000 pounds per acre.

• Applying the material to fill areas causes more harm than good. Plants will put on too much vegetative growth, which is detrimental to grain yield.

• On poor, sandy soils, the material may be applied generally to cut areas and lighter throughout the rest of the field.

• Regardless of the soil type, regular fertilizer programs should be followed uniformly throughout the field.

• There appears to be residual benefits the following year, making back-to-back production a possibility.

• Ideally, the material should be applied between Dec. 1 and the end of January.

• Provide spreader truck operators with maps that indicate cut or low-yield areas to ensure applications are made in the right places at the correct rate.

“It’s a really good supplement, but not in lieu of other fertilizers,” Woods says. “It is excellent where you have a field with a cut area that is weak, and apply it only where the cut area is. If you use it in a fill area, however, excessive fertility can work against you.”

Economics vs. environmental benefits Ask questions, weigh costs vs. benefits before buying ‘alternative’ fertilizers
By Alan Goforth
Dr. Fred Turner once had lofty ambitions for the future of alternative fertilizers in rice production. “What I originally hoped to accomplish when I began working with sludges was to have a product that they would pay farmers to take instead of paying to take it to a landfill,” says Turner, professor of soils and plant nutrition at Texas A&M University in Beaumont, Texas. “That hasn’t happened yet, and farmers are paying for it.” Even so, many farmers are finding that sludge, poultry litter and other non-synthetic fertilizers are helping boost production and reduce input costs. “Alternative fertilizers are something to consider,” Turner says. “There are certain situations where they have some advantages. They are clean materials that are not toxic to the environment. Putting it in the soil instead of the landfill is a good way to manage nutrients and waste products that can benefit everyone.” Broad definition The first thing to understand about alternative fertilizers is that the term can encompass a wide range of materials. “In some contexts, it could mean any fertilizer, natural or synthetic, that is not commonly used by farmers growing a particular crop,” says Dr. Stuart Pettygrove, Extension soils specialist at the University of California, Davis. “In another instance it could be restricted in meaning to ‘natural’ or ‘organic’ fertilizers.” Organic farmers, for example, typically apply animal manure, green manure or both, he says. Green manure is simply a legume cover crop that captures atmospheric nitrogen and leaves it in the soil for the next rice crop. “It is difficult to say what an ‘alternative fertilizer’ is,” Pettygrove says, “but I suppose you could say that for conventional rice farming in the United Sates, municipal biosolids, animal manure and other so-called waste products would qualify as alternative fertilizers.” The use of alternative fertilizers on conventional rice is far from widespread. “I have not kept up on use of alternative fertilizers, but I think usage is quite small in California rice culture,” Pettygrove says. The same holds true in the Mississippi Delta, says Dr. Timothy W. Walker, Mississippi State University assistant agronomist in Stoneville, Miss. “Alternative fertilizers at the most would contribute to less than 1 percent of the total fertilizer used for rice production in Mississippi,” he says. “Poultry litter (pelletized or liquid formulations) and Unity (an ammonium sulfate-like product made with sewage sludge) would be the most commonly used alternative fertilizer sources.” Agronomists typically recommend alternative fertilizers as a supplement to—not a replacement for—conventional fertilizers. They can work well in specific situations, such as cuts in recently graded fields. Counting the costs Despite the environmental benefits, the challenge is to make the economics work. “Growers try out alternative fertilizers in the hope of improved efficiency (i.e., the plant capturing more of the applied nutrient) and, therefore, reducing the amount of nutrient that must be purchased,” Pettygrove says. “Or they may be looking for a beneficial side effect, such as fewer weeds and plant diseases. “Conventional materials are almost always the least expensive per unit of available nutrient. Less-concentrated fertilizers such as manures, biosolids and chicken litter pellets lead to higher application costs and, possibly, less-uniform application.” The bottom line must balance environmental impact aginst costs. “Rice farmers select fertilizing materials almost exclusively based on yield impact and cost,” Pettygrove says. “Recycling of waste products (manure or biosolids) to rice crop land may be an environmentally sound alternative to disposing of them in landfills or on vegetable cropland. “For the manures and biosolids, the benefit could be (but must be proven) a longer-lasting effect of some of its nutrients, especially N, P, Fe and Zn, compared to inorganic sources of these nutrients. This benefit, when it occurs, is due mainly to the organic matter in these materials.” However, simple logistics can quickly erase the potential benefits of alternative sources of fertilizers. “Poultry production is located in the east-central part of Mississippi, which makes it difficult to transport to the Delta,” Walker says. “If transportation were not a factor, poultry litter would be a good soil amendment on precision-leveled soils with some nutrient benefits as well. “In addition, it would help poultry producers discard this byproduct, which has environmental implications for poultry producers. But the economics of transporting poultry litter to the Delta are not feasible.” Finally, factor in the amount of alternative fertilizer required to make a crop. “Those who are interested in placing alternative fertilizer products on the market must understand the amount of nitrogen needed to grow a crop,” Walker says. “In Mississippi, approximately 180 pounds of actual N is needed to produce the crop. Low-analysis products just do not fit our production practices.” Before you buy ‘alternative’ fertilizers, ask these questions: What is the composition? “When you apply chicken litter, you are never sure if it is 2 percent nitrogen or 5 percent nitrogen,” says Dr. Fred Turner with Texas A&M University. Don’t be afraid to ask for documentation, adds Dr. Tim Walker, with Mississippi State University. “Any fertilizer or soil amendment must be tested by the Mississippi State Chemical Laboratory before being sold,” he says. “This reduces the risk of producers buying products that do not have a guaranteed analysis.” How will it be applied? “The method of application is critical for any alternative fertilizer or soil amendment,” Walker says. “If the product cannot be distributed uniformly with commonly used application equipment (sprayers or spreaders), chances are it will not fit into a production setting.” The economics of application favor conventional products. “One thing that is unique to rice production is that a lot of fertilizer is still applied with an airplane,” he says. “Airplane costs are based on pounds of product applied; hence, the higher grade the material, the less expensive for application, and vice versa.” How will it perform in my operation? “All farmers should consider testing materials on a small part of their acreage as part of their ongoing research,” says Dr. Stuart Pettygrove with the University of California, Davis. “However, many farmers find it too time-consuming and costly to do this. “To get a true picture, replicated strips or plots are required, and the test must be run over several years. Yield monitors on rice harvesters have created a new, less-expensive method for carrying out on-farm trials without having to obtain a small-plot harvester and weigh wagon.” What is the availability? “Look at accessibility and availability,” Turner says. “Everybody wants fertilizer right before they plant. Will it be available when you need it?” Does it sound too good to be true? “Does the advertising for the product rely on scientific-sounding mumbo jumbo?” Pettygrove says. “References to enzymes, humic substances or vitamins should raise a caution flag. Don’t forget to check with your Extension agent or farm advisor.” In the final analysis, the acceptance of alternative fertilizers, as is the case with most inputs, comes down to price and performance. “If alternative fertilizers can compete with the prices that we have with synthetic products and can be applied uniformly without expensive equipment modifications,” Walker says, “then the use may expand.” Biosolids make the grade for Texas producer Leveling rice fields solves one problem while creating another. “You lose all of your topsoil and its nutrients,” says Dr. Fred Turner, professor of soils and plant nutrition at Texas A&M University. “It is impossible to make maximum yields without adding organic matter after leveling land.” Des Woods, who farms in the Katy area of Texas near Houston, has found a cost-effective solution by applying municipal waste. The waste, a 6-2-0 fertilizer, is called Vital-Cycle. “We use it where we do laser work and have cut areas where we need to bring the fertility back,” he says. “It costs $32 an acre applied.” Vital-Cycle comes from site-specific plants in Houston that receive only residential and restaurant waste, which reduces the problem of high heavy metal concentration found in industrial waste products. Pathogens are eliminated by a multi-step process that begins with microbial decay and ends with the material being heated to 1,200 degrees to eliminate any remaining micro-organisms. In a recent 18-month study, scientists at the University of Arizona documented that Staphylococcus aureus, a human disease pathogen, is not present in processed biosolids. Woods makes these observations from his four years of experience with biosolids: • On rich, healthy soils, cut areas benefit from an application of 1,000 to 2,000 pounds per acre. • Applying the material to fill areas causes more harm than good. Plants will put on too much vegetative growth, which is detrimental to grain yield. • On poor, sandy soils, the material may be applied generally to cut areas and lighter throughout the rest of the field. • Regardless of the soil type, regular fertilizer programs should be followed uniformly throughout the field. • There appears to be residual benefits the following year, making back-to-back production a possibility. • Ideally, the material should be applied between Dec. 1 and the end of January. • Provide spreader truck operators with maps that indicate cut or low-yield areas to ensure applications are made in the right places at the correct rate. “It’s a really good supplement, but not in lieu of other fertilizers,” Woods says. “It is excellent where you have a field with a cut area that is weak, and apply it only where the cut area is. If you use it in a fill area, however, excessive fertility can work against you.”
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