Journal of the NACAA
ISSN 2158-9429
Volume 2, Issue 1 - September, 2009

Editor:

Wheat (Triticum aestivum) Response to Fall vs. Spring Manure Application

Wiederholt, R.J., Nutrient Management Specialist, North Dakota State University

ABSTRACT

WHEAT (Triticum aestivum) RESPONSE TO FALL VS. SPRING MANURE APPLICATION Wiederholt, R. J. Nutrient Management Specialist, North Dakota State University, Carrington Research Extension Center, Carrington, ND 58421 The timing of manure application is usually determined by environmental protection issues or farm operation workload. Little information is available concerning the effect of manure application timing on manure nutrient availability. A randomized complete block study with four replications was established at the North Dakota State University Carrington Research Extension Center to determine the impact of fall versus spring applied livestock manure on hard red spring wheat growth and yield. Four treatments were imposed on 15' x 30' plots; 1) zero nitrogen (N), 2) fall applied manure, 3) spring applied manure and 4) spring applied urea N. The N treatments were applied to meet a 60 bushel ac-1 wheat yield goal. The plot area was no-till with no incorporation of the treatments except that the urea N was applied during a light rain to minimize volatilization. Plant height, spike count, yield, test weight and kernel protein was determined at maturity. According to statistical analysis, the check treatment was significantly shorter than the other treatments and there was no difference among the treatments for test weight or spike count. The urea N treatment had significantly higher protein than the other treatments and for yield, urea > fall manure > spring manure > or = the check. The results of this study suggest that timing of manure application may impact crop yield.

Introduction

Many questions are asked concerning the right time to apply manure.
The standard recommendation is to apply manure in the fall on fields that have a low risk of runoff or other environmental impacts and to spring apply manure on fields with a high environmental impact risk to reduce the time of exposure to runoff or snowmelt.
However, very little research has been conducted to look at the application timing effect on nutrient availability from livestock manure applications. One multi-year study conducted in WI looked at fall vs. spring applied dairy manure (1). The results of that study showed that weather conditions had an impact on nutrient availability. Spring applied manure nutrient availability was less than fall applied under colder than normal spring temperatures. When spring temperatures were warm, there was no difference in crop response to manure application timing. However, no data is available to determine the response of manure application timing on nutrient availability in the Upper Great Plains. To answer this question a study was initiated at the Carrington, ND Research
 
Extension Center (CREC) to determine the impact of fall vs. spring applied beef feedlot manure on hard red spring wheat yield.
 

Materials and Methods

A randomized complete block study with four replications andfour treatments was initiated in the fall of 2007. The plot size was 15’ by 30’ and all treatments were applied by hand. Treatments included; fall applied manure, spring applied manure, spring applied urea N and a check with no N. To challenge the availability of the manure N, the plot area was no-tilled. The treatments were applied to supply 114 lbs of N ac-1 plus soil residual N for a target wheat yield of 60 bu ac-1. The fall manure was applied on 11/16/07, spring manure on 4/14/08 and urea on 4/23/08.
The urea was applied during a light rain to decrease volatilization losses. The wheat was planted on 4/30/08 and harvested on 8/19/08. At the boot stage, a normalized differentiated vegetative index (NDVI) reading was taken using a near infrared sensor to determine any differences in plant color that could be correlated to N level in the plant.
 
At maturity, plant height, spike count, yield, test weight and protein were determined.

Results

According to Table 1, there was no difference in plant height except the ureatreatment was significantly taller. The NDVI was not different except the check was significantly less than the other treatments. For yield, urea > fall manure > spring manure > the check. Protein was similar among the treatments except the urea treatment had significantly higher protein than the other treatments. There was no difference among the treatments for spike count or test weight.
 
Table 1. Response of Hard Red Spring Wheat to Fall and Spring Applied Manure
 
 
 
Spike
 
 
Test
 
 
Height
Count
NDVI
Yield
Weight
Protein
Treatment
(cm)
(spikes m-1)
(% VI)1
(bu ac-1)
(lb bu-1)
(%)
Check
71 b2
9.5
0.34 b
26 c
63
13.1 b
Spring Urea
82 a
12.3
0.53 a
51 a
62
15.2 a
Fall Manure
75 b
11.6
0.50 a
39 b
63
13.4 b
Spring Manure
73 b
11.9
0.47 a
34 bc
63
13.3 b
 
1VI=vegetative index, the darkness and volume of green per plant 2LSD=0.05

Discussion

In previous manure utilization studies conducted at the CREC, manuretreatments have produced similar yields when compared to commercial N treatments.
 
However, these results, are similar to the WI study. The weather conditions played a role since it was extremely dry in the fall of 2007, there was no appreciable snow over the winter, temperatures were below normal in the spring of 2008 and there was no spring rainfall until very late May of 2008. Manure N needs to be converted by soil bacteria from an organic to an inorganic form to be available for plant uptake. For this to happen, the soil bacteria require adequate moisture and heat. Because of the dry and cold conditions of fall 2007 and spring 2008, the soil bacteria where inhibited from converting the manure N to plant available N. By the time the crop received rain in late May, the bacteria were able to convert the manure N but it was too late for the crop to utilize it because wheat is a short season crop with high N demand early in the growing season. The bacteria did have more time to convert the manure N from the fall applied manure but since it was so dry, conditions were still not sufficient for the manure treatments to yield as well as the urea treatment. This study will be repeated in 2009 to determine the results under different growing conditions.
 

Conclusion

Soil microbes require sufficient heat and moisture to mineralize manure N.Therefore, the timing of livestock manure application may have an impact on N availability under adversely dry or cold growing conditions.
 

References

1. Timing of Manure Applications to Cropland to Maximize Nutrient Value, Karen A. Talarczyk, K. A. Kelling and T. M. Wood, in proceedings Manure Management Conference February 10-12, 1998, Ames, Iowa, http://www.p2pays.org/ref/21/20003.htm.