Nutrient Studies

Corn Farm Research Nutrient / Soil Fertility Studies

Farm research studies in this section include nitrogen rate/application/timing studies, manure application, laboratory comparisons, and other nutrient studies. 

All studies are pdf documents and require Adobe Acrobat Reader. Download free.

Related NebGuide:  Soil and Water Summaries for 2005-2006.

Nitrogen Rate/Application/Timing Studies

Objective:  Determine the profitability of using 11-52-0 surface broadcast prior to planting in a corn and soybean rotation.
Summary: The application of 11-52-0 broadcast increased seed yield of soybeans in 1997 and 1999. Corn grain yields were increased by the 11-52-0 broadcast in 1998. In 2000, phosphorus broadcast increased grain yield (9 bu/ac) and test weight (0.4 lbs/bu). Tillage also increased grain yield (10 bu/ac) and reduced grain moisture at harvest slightly. In 2001 broadcast phosphorous increased the seed yield of soybeans 6 bu/ac. In 2002, broadcast phosphorus increased grain yield and test weight and reduced grain moisture at harvest. Tillage done in 2000 and 2001 resulted in reduced yields and grain moisture at harvest and increased test weights in 2002. Residual effects of phosphorus gave increased seed yield and a slight increase in seed moisture in 2003.

Objective:  Determine the profitability of anhydrous ammonia fertilizer verus liquid (28%) fertilizer at two application rates in corn production.
Summary:  (Minchow) The anhydrous ammonia fertilizer treatments yielded significantly higher than the liquid (28%) fertilizer treatments. High rate treatments of both fertilizer sources also produced significantly higher yields than low rate treatments. (Hellerich) A significant yield difference was found between the preplant and split sidedress fertilizer applications. Although fertilizer rates did not significantly impact yield, application timing did. It appears that delayed application was beneficial, however, further testing is desirable.

Objective:  Determine and document the effect of ammonia placement on the profitability of non irrigated corn production.
Summary:  In 2005 & 2006, ammonia placement had no effect on yield or grain moisture of corn at harvest.

Objective:  Determine the profitability of two liquid nitrogen application rates at planting and two sidedress anhydrous ammonia rates in corn production.
Summary:  In 1994 anhydrous ammonia sidedress fertilized corn yield was significantly higher than liquid (28%) nitrogen treatment. High rate treatments of both anhydrous ammonia and liquid (28%) nitrogen yielded significantly higher than low treatment rates. The interaction among fertilizer sources and rates was also significant to yields. The low rate of liquid (28%) yielded poorly. In 1995 yields were increased by higher rates of liquid nitrogen, but not by anhydrous ammonia. Nitrogen loss was observed during the high rate application of anhydrous ammonia. In 1996 yields were increased by higher rates of nitrogen. There was no difference between liquid and anhydrous ammonia fertilizers.

Objective:  Determine the profitability of using UAN with two percent attapulgite versus UAN alone in irrigated corn production.
Summary:  In both studies, the application of attapulgite clay had no significant effect on the yield or grain moisture of corn in 2007. UAN (180 lbs. N/ac) with attapulgite clay that was applied on May 11 (McKenzie).  UAN (84 lbs N/ac) with attapulgite clay was applied with planter (Mulliken).

Objective:  Determine and document the profitability of nitrogen fertilizer rates and application timing in irrigated corn.
Summary:  In 2006, the rate of applied nitrogen had no significant effect on grain yield (weigh wagon or monitor) or grain moisture in either study. NH3 cost $490/T, NH3 application cost included ($7.40/ac) UAN cost $245/T. UAN application cost included ($5/ac). In 2007, increasing the rate of applied nitrogen resulted in an increase in grain yield (weigh wagon or yield monitor), however, there was no significant difference between the highest rate (158 lbs/ac) & the UNL economic rate (119 lbs/ac). Grain moisture at harvest was not affected by rate of applied nitrogen. In 2008, grain yield was highest with the highest rate of applied nitrogen in both studies. Splitting the application also resulted in maximum yield in the irrigated study. Grain moisture at harvest was not affected by nitrogen treatment. Results were the same using weigh wagon or monitor.

Objective:  Determine the profitability of using starter fertilizer versus using none in corn production.
Summary:  Variable results occurred regarding increased grain yield from addition of starter fertilizer in these studies.  (Uehling) The use of starter resulted in a significant increase in grain yield in 2005, but not in 2006 or 2007.  (Quad) Starter fertilizer showed no significant yield advantage when compared to no starter on seven irrigated corn fields in south central Nebraska. (Schmidt) The use of starter fertilizer resulted in slightly drier grain at harvest and a slight increase in grain yield.  (Hanke) Use of starter fertilizer increased early growth and grain yield and resulted in lower grain moisture at harvest in 1997-1998. There was not a significant difference in performance between the two starter fertilizers. (Ohnoutka) Soybean seed yields were increased by starter fertilizer (10-34-0), in 1997. No differences were detected in the corn comparison. In 1998 starter fertilizer use resulted in slightly drier corn at harvest and slightly lower test weight. No differences were detected in the soybean trial. 

Objective:  Study effect of side-dress Nitrogen application on corn production and profitability
Summary: The addition of 40#/ac. side-dress Nitrogen did not result in an increase of rainfed corn yield (Fujan 2012).  The addition of 35# and 60# of nitrogen per acre sidedressed, did no increase irrigated corn grain yield, moisture or test weight (Sladky 2012).

Objective:  Study effect of starter application on corn production and profitability
Summary: There was no signficiant difference in yield between 10-34-0 + zinc vs. SuperStarter in 2012 (Makovicka). Based on only two replications there was a significant increase in yield of all treatments compared to the check in 2012. The cost of some of the treatments was not justified based on this year’s data. The starter (10-34-0) had the best return on investment. (Stahr)

Back to top

Manure Application

Objective:  Determine the profitability of using feedlot manure as a replacement for commercial fertilizer.
Summary:  (Hanson) In 2001 the use of multi-nutrient fertilizer and either manure source produced similar corn yields. Soybeans produced the same seed yield with the manure sources, but the no fertilizer treatment was lower than the other treatments. In 2002 the use of multi-nutrient fertilizer and both manure sources produced the same corn yields. Manure from the west lagoon produced slightly lower seed yield in soybeans. Grain moisture of corn at harvest was the highest where only nitrogen fertilizer was applied. Using a multi-nutrient fertilizer resulted in lower grain moisture which was reduced further when manure was applied. In 2003 corn yields in corn following corn were highest following residual mixed fertilizer or manure. Yields were not affected when corn followed beans. Grain moisture at harvest was not affected by treatments.
(Larson) The application of K and S in addition to NPZn increased grain yield significantly in 1999. Yield from this treatment was equal to the yield from manure. Test weight was slightly lower for the NPZn treatment when compared to the NPKSZn treatment. There was a slight carry-over effect on soybeans in 2000. Seed yield from the manure treatment was slightly higher than from the NPKSZn treatment. In 2001 grain test weight was increased by KS and increased more by manure. Yield and grain moisture were not affected by treatments.
(Moravik) The application of 30 tons of manure per acre (230 lbs/ac plant available nitrogen) resulted in a grain yield that was higher than was achieved with 180 lbs/ac nitrogen from commercial fertilizer. The addition of nitrogen with the manure increased yields above manure alone. (Bartek) Use of manure resulted in higher grain yields than using commercial fertilizer in 1996, however, the grain was wetter at harvest. In 1997 soybean seed yield was higher where manure was applied in 1996. In 1998 corn grain drier where manure was applied in 1996. Grain yield was also significantly different.
(RaikesField1) Corn yields were the same for manure treatments and for fertilizer treatments except for the treatment designated "fertilizer only." The reason is unknown. This treatment had the lowest average plant population, however, plant population was not related to treatment and this treatment had an average population similar to the liquid 1996 treatment. The use of manure did result in higher grain moisture at harvest and a slightly lower grain test weight in corn in 1996. The application of manure had no effect on soybeans in 1997. 
(RaikesField2) In 1996 the use of manure prior to growing soybeans resulted in a reduction in seed yield and a lower test weight. The use of manure did not affect seed moisture at harvest, however, the use of liquid manure did give slightly lower seed moisture than where solid manure was used.  The application of manure in 1997 resulted in higher grain moisture and lower yields as compared to treatments that received fertility only or fertilizer in 1997 and manure in 1996.

Back to top

Laboratory Tests and Credits

Objective:  Determine the profitability of nitrogen application rates based on soil organic matter content.
Summary:  Corn yields were increased with each increment of nitrogen applied. Test weight was reduced by the lowest rate of nitrogen applied. Plant population was slightly higher at the mid-rate of nitrogen, however, population does not appear to be a factor in grain yield.

Objective:  Determine the profitability of fertilizer treatment recommendation by two different soil laboratories.
Summary:  In 2004, soybean growth was not influenced by fertilizer treatment. Corn growth was not affected by fertilizer treatment in 2005. In 2006, soybeans fertilized according to commercial laboratory yielded slightly more than the other treatments. Soybeans from plots that received only nitrogen on corn the previous year were slightly drier at harvest., In 2008, soybeans fertilized according to a commercial seed laboratory had wetter seed at harvest compared to UNL or none treatment. 

Objective:  Compare different methods of crediting legumes and determine the profitability of three treatments in corn/soybean rotation.
Summary:  Based upon 2004-2005 data in South Central Nebraska, under irrigated conditions, producers should be able to credit 1lb of nitrogen/bu. beyond the 45 lbs where beans yield 65 or 75 bushels and be fairly safe. It would be a good idea to collect some soil samples for residual nitrogen following soybeans and conduct some strip tests on your individual farm to see responses under your conditions.

Back to top

Other Nutrient Studies

Objective:  Determine the profitability of phosphorus fertilizer placement in the production of corn and soybeans.
Summary:  The use of phosphorus fertilizer significantly increased grain yield in 1999. Broadcast application increased yield above the no phosphorus treatment, and banded application increased yield above the broadcast treatment. Test weight was increased by both phosphorus treatments. There was no carryover effect on soybeans in 2000.

Objective:  Determine the profitability of using potassium fertilizer in a corn and soybean rotation.
Summary:  In 2001 potassium had no effect on corn growth and yield. Plant density was reduced very slightly. In 2002 soybean growth and seed yield were not affected by residual potassium applied in 2001. In 2003 the application of potassium increased grain test weight slightly. In 2004 residual potassium from 2003 had no effect on the growth and yield of soybeans.

Objective:  Determine the profitability of using APSA-80 soil conditioner, Nutriplant seed treatment in irrigated corn.
Summary:  Applied treatments had no significant effect on grain yield, grain moisture, test weight or harvest populations in 2007.

Objective:  Determine the profitability of using iron fertilizer on corn.
Summary: (Buller) Grain yield was not affected by the fertilizer treatment, however, grain moisture was lower at harvest where fertilizer was applied. This product was prone to clotting and plugging screens.  (Soukup) The use of iron fertilizer resulted in a significant reduction in grain yield. Reason cannot be explained. No differences were observed in field during crop growth.

Objective: To determine & document the effect of replacing commercial fertilizer with alternate products on the profitability of corn production.
Summary: Grain yields and grain moisture at harvest were not affected by any of the treatments applied in 2009.

Objective: To determine & document the effect of using Torque on the profitability of producing corn.
Summary: Torque had no effect on grain yield; however, moisture at harvest was slightly lower.

Objective: To study the effect of Generate Starter on corn production and profitability.
Summary: The Generate treatment did not result in an increase of irrigated corn yield.

Objective:  Study effect of sulfur on corn production and profitability
Summary: For this study with hybrid Big Cob 15-80, there was no statistical yield difference due to the addition of sulfur.

Back to top