NUTRIENT MANAGEMENT QUIZ

Brian Johnson, owner of Elceed Farm in Westover talks about the benefits of using chicken litter manure as fertilizer on his crops.

How well do you know your nutrient facts?

As the phosphorus debate rages, how much agricultural, scientific knowledge do you have?

EDDIE JOHNSON

Test your soil nutrient IQ. All are true-false questions. Score one point for each correct answer, subtract a point for each blank answer and subtract two points for each incorrect answer. This will minimize guessing.

1. Phosphorus is an essential nutrient for plant growth. However, many crops — such as corn — require only one-third to one-fourth as much phosphorus as nitrogen for economically optimum yields. Since poultry litter contains about the same amounts of each, this means phosphorus has often been over applied to agricultural fields. Over time, this has caused a buildup of phosphorus in many soils to values well above those required for optimum crop yields. This is a concern because increased soil phosphorus levels can contribute to a greater risk of phosphorus loss to the environment and lead to ecological problems, such as eutrophication (enrichment of an ecosystem with chemical nutrients, typically compounds containing nitrogen, phosphorus or both) of surface waters.

2. Manure is phosphorous-laden according to the extreme environmentalist; however, it contains only 3 percent phosphorous.

3. Land management strategies: Most states have addressed this issue by placing restrictions on land application of poultry litter (or other phosphorus sources) to soils considered “high” in phosphorus. For example, the Delaware Nutrient Management Act stipulates that “high P” soils may receive no more litter or fertilizer phosphorus than is removed by crop harvest during a three-year planning period. The Delaware Nutrient Management Commission currently defines a “high P” soil as one with a soil test P value greater than 150 FIV (fertility index values). This approach prevents the continued over-application of phosphorus to cropland and should lead to improvements in water quality. However, limiting litter applications to crop phosphorus removal requires more land to use the poultry litter generated in Delaware today. Many producers who had previously used poultry litter to supply nitrogen to crops also must now purchase commercial fertilizer nitrogen to meet crop needs, thus increasing their production costs. This is the same law, with more restrictions, that is in Maryland. It is field-specific and strictly limits phosphorous application.

4. Extensive research in the past 10 years has shown poultry diets can be modified to reduce litter phosphorus concentrations by 25 percent to 50 percent. Diets modified to reduce phosphorus excretion have been widely adopted by Delaware poultry companies, resulting in the need for new guidelines on the phosphorus content of poultry litter.

5. Research shows improving poultry diets reduces phosphorus in poultry litters.

6. The Environmental Protection Agency is using data from the late 1980s and early 1990s to estimate nitrogen and phosphorous generation from agriculture and food production systems.

7. A nutrient management plan is a farmer’s “business plan” for nutrients. The more efficiently fertilizers are used, the less nutrients escape to waterways. A plan is developed by a certified nutrient consultant and includes contents such as maps, soil analysis, manure analysis, crop yield goals and a budget for nutrients.

8. Analysis of more than 3,400 manure samples by the DDA laboratory from poultry farms in Delaware revealed a significant trend down in phosphorous.

9. Winter application regulations continue, and limit the application of commercial land manure based fertilizer during the time of the year that is most vulnerable for nutrient runoff.

10. Early science said phosphorous only left the field when soil erosion occurred, as each particle held the phosphorous. If the soil behind the Conowingo Dam (with phosphorous attached) were removed, it would help the Chesapeake Bay quickly.

11. Eighty percent of the water flows into the bay from north of the Lower Shore.

12. Hurricane Sandy forced millions of gallons of sewage spills on the Lower Shore.

13. The Maryland Agricultural Water Quality Cost-Share Program provides farmers with grants to cover up to 87.5 percent of the cost to install conservation measures known as best management practices on their farms to prevent soil erosion, manage nutrients and safeguard water quality in streams, rivers and the Chesapeake Bay. Grassed waterways planted to prevent gully erosion in farm fields, streamside buffers of grasses and trees planted to filter sediment and farm runoff, and animal waste management systems constructed to help farmers safely handle and store manure resources are among more than 30 BMPs currently eligible for MACS grants. In the past 15 years, Maryland farmers have spent $15.8 million of their own money to match these grants.

14. For tens of thousands of daily visitors to Baltimore’s Inner Harbor, the water serves as a picturesque backdrop and an inviting diversion, but visitors should think twice before trailing an arm along the water’s edge. A water sample tested on July 7, 2010, revealed the bacteria level in the Inner Harbor to be almost five times the safe limit for human contact.

15. The bay provides a winter home to more than a million waterfowl each year. The amount of fecal material produced by a goose each day can vary. Geese defecate from 28 to 92 times per day, with wet weights of the fecal material averaging from 1 to 3 pounds. When in water, the decomposition of organic materials from the feces reduces dissolved oxygen levels. Canada geese excrete 1.15-3.11 pounds of Kjeldahl nitrogen per goose each year — and 0.36-1.41 pounds of phosphorus per goose each day. The nitrogen and phosphorus act as fertilizers, which can cause eutrophication in a body of water.

16. A red cow can eat green grass, gives white milk and brown pooh. Isn’t nature amazing?

All of the above statements are “true.”

Eddie Johnson is a retired farmer who lives in Westover, and a former member of The Daily Times Editorial Board.