Presentation is loading. Please wait.

Presentation is loading. Please wait.

Long-Term Field Research for Developing Nitrogen BMP’s Gyles Randall Univ. of Minnesota Southern Research and Outreach Center

Similar presentations


Presentation on theme: "Long-Term Field Research for Developing Nitrogen BMP’s Gyles Randall Univ. of Minnesota Southern Research and Outreach Center"— Presentation transcript:

1 Long-Term Field Research for Developing Nitrogen BMP’s Gyles Randall Univ. of Minnesota Southern Research and Outreach Center grandall@umn.edu http://sroc.coafes.umn.edu/

2

3 Factors relating to BMP’s for N Cropping systems N rate applied Time of application Nitrification inhibitors N source Tillage Cover crops

4 CROPPING SYSTEMS

5 Effect of CROPPING SYSTEM on drainage volume, NO 3 -N concentration, and N loss in subsurface tile drainage during a 4-yr period (1990-93) in MN. CroppingTotalNitrate-N SystemdischargeConc.Loss Inches ppmlb/A Cont. Corn30.428194 Corn – Soybean35.523182 Soybean – C35.422180 Alfalfa16.4 1.6 6 CRP25.2 0.7 4

6 Nitrate losses in tile drainage water from soil mineralization. Dry years Established grass

7 CONCLUSION Cropping system has greater effect on hydrology and nitrate losses than any other management factor! “Preventive Management”

8 RATE OF APPLICATION

9 Continuous Corn, 2001–03 Olmsted Co.

10 Effect of N rate for corn after soybean on NO 3 -N concentrations in tile drainage water in 2001.

11 Effect of N rate on yield of corn after soybean, net return to fertilizer N, and nitrate-N concentration in tile drainage at Waseca (2000–2003). N Treatment4-Yr YieldNet4-Yr FW TimeRateN-ServeAvg.ReturnNO 3 -N conc. lb /Abu/A$/A/Yrmg/L --- 0 111--- Fall 80Yes144 3012 “120“166 7013 “160“172 7818 Spr.120No18010514

12 Effect of N rate applied for corn in 2003 on nitrate-N concentration and loss in tile drainage during May–September 2004 from soybeans at Waseca. NFW Nitrate-NNitrate-N Rate.ConcentrationLoss Lb/Amg/LLb/A 80 936 1201252 1602081

13 Conclusion Corn yields were increased 5% and nitrate losses in drainage were reduced by 27% when reducing the N application rate from 160 lb/A applied in the fall to the recommended 120-lb rate applied in the spring. Reducing the N rate from 120 lb/A to 80 lb/A reduced yield by 17% and nitrate loss by 13%. Forty-six percent of the nitrate lost in tile drainage from a corn-soybean rotation was lost in the year soybeans were grown.

14 TIME OF N APPLICATION

15 Effect of time of N application and N-Serve on corn yields after soybean from 1987–2001 at Waseca. Time of N Application ParameterFallFall+N-ServeSpring 15-Yr Avg. Yield (bu/A)144153156 15-Yr Avg. Economic return over fall N ($/A/yr) * ---$9.30$18.80 7-Yr Avg. Yield (bu/A) **131146158 7-Yr Avg. Economic return over fall N ($/A/yr) * ---$22.50$51.00 * Corn = $2.00/bu; N = $0.25/lb N ** Seven years when statistically significant differences occurred.

16 Nitrate-N concentration in tile drainage from a corn-soybean rotation as influenced by time of N application and N-Serve at Waseca. N Treatment Time of applicationN-ServeNitrate-N Conc.* -- mg/L -- FallNo14.1 FallYes12.2 SpringNo12.0 * 10-cycle (1990-2000) rotation average.

17 1999 tile water NO 3 -N loading at Waseca vs. NO 3 -N concentrations in the Le Sueur River 2.3 miles from Mankato.

18 Conclusion Compared to late fall N application without N- Serve over the 15-year period: –Corn yields were increased 9 and 12 bu/A/yr (6 and 8%) by either fall N+N-Serve or spring preplant N, respectively. –Nitrate losses were decreased 14 and 15% by either fall N+N-Serve or spring preplant N, respectively.

19 Region Specific BMPs for N

20 Proposed BMP’s for South-Central MN Recommended –Spring preplant or split applications of ammonia, urea, or UAN are highly recommended. –Incorporate broadcast urea or preplant UAN within three days. –Apply sidedress application before corn is 12” high. –Inject or incorporate sidedress applications of urea or UAN to a minimum depth of 4 inches.

21 Proposed BMP’s for South-Central MN cont. Recommended, but with greater risk –Fall application of AA + N-Serve after soil temperature at 6-inch depth is below 50° F. –Side dressing all N before corn is 12 inches high. Not recommended –Fall application of urea, UAN, or anhydrous ammonia without N-Serve

22 THANKS Gyles Randall grandall@umn.edu Southern Research and Outreach Center grandall@umn.edu http://sroc.coafes.umn.edu/


Download ppt "Long-Term Field Research for Developing Nitrogen BMP’s Gyles Randall Univ. of Minnesota Southern Research and Outreach Center"

Similar presentations


Ads by Google