Soils for July 27, 2000

The last five years have been extremely volatile in terms of farm yields, income and fertilizer use. Fertilizer use generally follows the excitement to farm, and this is shown in the data of fertilizer use from 1995-1999. These figures differ from those in the ND Ag Statistics publication because these figures are from January to December, whereas the Ag Statistic numbers are from July through June. But regardless of the actual numbers, the trend tells a story.

Nitrogen Product	Tons
Nitrogen Product	Year
	1995	1996	1997	1998	1999
NH₃	350,240	492,753	418,112	345,664	366,967
Urea	294,561	254,014	310,508	319,124	348,453
34-0-0	11,311	12,049	9,105	1,901	1,920
Total N– all grades	501,971	607,065	570,346	531,773	516,434

Anhydrous ammonia use in 1998 and 1999 is very similar to 1995. 1996 was a year of higher crop prices, or at least the prospect for these prices was high and the farm program changed. Soil conditions allowed the widespread use of ammonia, which is contrary to relatively miserable fall conditions in 1997 and 1998. Somewhat distressing is the continued decrease in the use of ammonium nitrate (34-0-0), which is the premier no-till surface applied fertilizer. There are still hold-out fertilizer plants in the western part of ND and a few isolated areas which provide this fertilizer, but not many. As a result, no-till farmers
must consider more risky and labor-intensive alternatives with volatile fertilizers, especially urea.

Urea use has gradually increased due I think to larger farms, short application seasons and an increase in site-specific farming.

Total N use peaked in 1996 with an increase in wheat acreage, but declined as crop prices fell and alternative crops, especially soybean acreage increased. An increase in broadleaf crop acreage as opposed to grassy crops would be expected to influence N availability due to faster mineralization of residues, a change in soil biology due to a broadleaf crop and lack of tie up of N due to high carbon straw.

Fertilizer Product	Tons
Fertilizer Product	Year
	1995	1996	1997	1998	1999
P₂O₅, all grades	184,159	205,174	211,661	201,273	173,624
90% Sulfur	1,288	2,920	3,411	3,400	2,782
21-0-0-24S	7,109	10,419	14,393	24,971	31,291
Total S– all grades	3,404	5,232	7,733	8,028	9,249

The lack of volatility in P fertilizer use is the result of relatively modest amounts applied each year. When an average of 40 lb/a of 18-46-0 or 10-50-0 are applied for most crops, there is not much room to lower rates. Some producers certainly chose not to use P fertilizers in 1998 and 1999, but the number that did so was not large. Rather, the increase in total use in 1997 was more likely modest rate increases or in some cases some movement towards building soil test levels on individual farms recently rented or purchased.

Although small in tonnage compared to N and P, sulfur use has dramatically increased since 1995 due to the dramatic increase in canola acres. With any crop, there is some background S use. The tonnage in 1995 of total S reflect some canola acreage, but also some standard use in sandy areas low in organic matter which respond to S application for other crops such as wheat. However the increase from 1995 to the present is the direct result of canola acreage.

The different trends between elemental S and 21-0-0-24S (ammonium sulfate) is encouraging because NDSU research by John Lukach at Langdon and Dr. Ed Deibert in Fargo at a site near Rock Lake showed conclusively that canola requires readily available sulfate sources of S, which apparently elemental sulfur sources are unable to provide. S use trends show an increase in all forms of S from 1995 to 1997, but elemental sulfur use has recently declined, while ammonium sulfate use continued its advance. Only 31% of total sulfur use today in elemental sulfur, whereas in 1995, it held about 50% of the market.