Ardell D. Halvorson and A.L. Black1

USDA-ARS, Mandan, ND

Contribution from USDA-ARS, P.O. Box 459, Mandan, ND 58554. The U.S. Departrnent of Agriculture offers its programs to all eligible persons regardless of race, color, age, sex, or national origin, and is an equal opportunity employer.

INTRODUCTION

Dryland wheat in the Great Plains has traditionally been planted in a crop-fallow rotation using conventional, mechanical tillage methods during the fallow period for weed control. As new herbicides became available and herbicide prices declined during the past decade, reduced- and no-till systems have been adopted by producers. Because of increased soil water storage efficiency with reduced- or no-till systems, the potential for cropping more intensively than with the traditional crop-fallow system is enhanced. In addition, continued use of reduced- or no-till systems in a crop-fallow rotation will accelerate the formation and growth of saline seeps which are caused by inefficient use of water by crops in the crop-fallow system of fanning. Great Plains research during the past decade indicates that more intensive crop rotations than crop-fallow are successful in many areas. The more intensive cropping systems also increase grain production, precipitation or water use efficiency, and reduce soil erosion potential. However, limited information is available on the economic sustainability of the more intensive cropping systems in the Great Plains (Dhuyvetter, et al., 1995).

This paper presents results from two USDA-ARS tillage and cropping systems studies conducted at Akron, CO and a tillage-nitrogen-cropping system study at Mandan, ND. The effects of tillage system on winter wheat-fallow yields and economic returns from Colorado will be presented in addition to the effects of nitrogen ~) fertilization on crop yields and economics from an adjacent no-till, annual cropping study. Grain yields from a dryland annual cropping system conducted at Mandan, ND will be contrasted to those from a spring wheat-fallow system. Tillage system and N fertilization effects on crop yields will be discussed as well as a partial economic analysis of the data.

Wheat-Fallow Tillage Study, Akron, CO. This research evaluated the costs and returns from three winter wheat-fallow production tillage systems: conventional till (CT), reduced-till (RT), and no-till ~T). Tillage systems consisted of CT, where seven tillages were performed with a sweep plow (undercutter) with 32-in. sweeps or a rodweeder; RT, where a mix of contact and residual herbicides were applied shortly after winter wheat harvest followed by three tillage operations as needed with a sweep plow (undercutter) or rodweeder until winter wheat planting in September; and NT, where a mix of contact and residual herbicides were applied shortly after winter wheat harvest followed by three additional contact herbicides applications as needed before winter wheat planting. Yield and production data (1987-1992) were used in making the economic comparisons. Duplicate sets of plots were available to provide wheat yield data each year from this Weld silt loam soil. Economic data were developed using 1991 estimated farm costs and Federal Farm Program requirements for a 1200 acre wheat-fallow farm in eastern Colorado with a 706 acre wheat base and farmer owned equipment. Set-aside acres (15% acreage reduction) were not included in this economic analysis. Cost comparisons were made using published custom rates for eastern Colorado. Herbicide costs were based on 1991 prices and application rates. Six year (1987-1992) average winter wheat price ($3.35/bu) was used with a deficiency payment of $0.6S/bu on a 32 bu/a proven yield. Details of this economic analysis were reported by Halvorson et al., 1994.

Winter wheat yields were not significantly different among tillage systems during any of the individual crop years. The average six year grain yields were 40,40, and 42 bu/a for the CT, RT, and NT systems, respectively. Therefore, an average yield of 40.4 bu/a was used in this analysis for all tillage systems since tillage system did not significantly affect yields. A summary of costs and returns on a 1200 acre dryland eastern Colorado farm using average yields (1987-1992), farmer-operator costs, and 1991 production prices and government program payments are shown in Table 1 and for custom operator costs in Table 2. When using farmer estimated costs of production (Table 1), estimated net returns to land, labor, and capital were 107% and 96% of the CT system for the RT and NT systems, respectively. When labor costs were included, net returns to land management, risk, and capital were 111% and 100% of CT for RT and NT systems, respectively. When custom rates were used for the tillage practices (Table 2), net returns to land, labor and capital were 123% and 110% of CT for the RT and NT systems, respectively.

Table 1. Summary of cost and returns on a typical 1200 acre dryland wheat-fallow farm in eastern Colorado with 600 acres of planted winter wheat using average yields (1987-1992), farmer-operator costs, and 1991 production prices and government program payments
	CT	RT	NT
Total grain, bu (600 wheat acres)	24,240	24,240	24,240
Gross returns, $	$93,684	$93,684	$93,684
Preharvest cost, $	$24,298	$24,276	$29,700
Harvest cost, $	$12,150	$12,150	$12,150
Total production cost, $	$36,648	$36,426	$41,850
Net return over production cost, $	$57,036	$57,258	$51,834
Ownership cost, $	$14,550	$11,916	$11,184
Total of all costs, $	$51,138	$48,282	$53,154
Return available for land, labor, capital, management, and risk $	$42,486	$45,342	$40,650
Estimated preharvest Labor, $6/hr	$3,240	$1,812	$1,254
Return to land, capital, management, and risk, $	$39 246	$43 530	$39 396
a Estimated preharvest labor hours: CT=540 hr; RT=302 hr; and NT=209 hr/1200 acres.Table 2. Summary of cost and returns on a typical 1200 acre dryland wheat-fallow farm in eastern Colorado with 600 acres of winter wheat planted using average yields (1987-1992), custom costs, and 1991 production prices and government program payments.

Table 2. Summary of cost and returns on a typical 1200 acre dryland wheat-fallow farm in eastern Colorado with 600 acres of winter wheat planted using averge yields (1987-1992), custom costs, and 1991 production prices and government program payments.
	CT	RT	NT
Total grain, bu (600 wheat acres)	24,240	24,240	24,240
Gross returns, $	$93,684	$93,684	$93,684
Preharvest cost, $	$42,708	$35,016	$39,390
Harvest cost, $	$12,150	$12,150	$12,150
Total production cost, $	$54,858	$47,166	$51,540
Net return over production cost, $	$38,826	$46,518	$42,144
Ownership cost, $	$5,760	$5,760	$5,760
Total of all costs, $	$60,618	$52,926	$57,300
Return available for land, labor, capital, management and risk, $	$33,066	$40,758	$36,384

The RT system had the highest projected potential returns per farm compared with CT and NT when using farmer estimated costs in this study. When custom rates were used for all operations, the net returns were RT>NT>CT. If costs or application rates of herbicides could be reduced, NT would become even more economically attractive. No-till affords the added benefit of leaving more crop residues on the soil surface, thereby reducing erosion potential. Assuming a situation of noncompliance for CT and compliance with NT, the per-acre return to land, labor, and capital would be $50 for CT and $67 for NT. Thus risk management must be considered when making decisions on which tillage system to use. The results of this study suggest that RT and NT Systems can be adopted by farmers without economic loss.

Dryland Annual Cropping Study, Akron CO. More intensive cropping requires additional N input to maintain economical yields, therefore, N requirements for optimum crop yields in a dryland, annual cropping system were studied. This study evaluated the response of spring barley, corn, winter wheat, and oat hay to N rate over a period of 10 years (1984-1993) in a dryland, annual cropping rotation. The details of this study and the crop yields were reported earlier by Halvorson and Reule (1994a; 1994b). The ten year yield data and cropping sequence are summarized in Table 3 along with N rates. This study was located adjacent to the Wheat-Fallow tillage study reported above. Six N fertilizer rates (0, 20, 40, 60, 80, and 120 lb N/a) were applied to the same plots for 10 crops on a Weld silt loam. The 120 lb N/a rate was 160 lb N/a the first two crop years of the study (1984 and 1985). This N rate was reduced because of a significant increase in residual soil

N03-N. Nitrogen rates were reduced 50% in 1988 because of crop failure caused by hail resulted in no measurable N removal in 1987. Nitrogen, as ammonium nitrate, was broadcast with no mechanical incorporation at planting. A no-till system was used with chemical control of weeds between crops and within the growing crop. The plot area was fallowed in 1983 using stubble mulch tillage

Grain/forage yields varied with crop and year (Table 3). Average annual grain/forage yields from ail crops over the 10 years of this study, including 1987 when the corn was hailed out (zero yield), were 1787, 2313, 2874, 3267, 3223, and 3371 lb/a for the 0, 20, 40, 60, 80, and 120 lb N/a treatments, respectively. This compares to an annualized winter wheat yield of 1233 lb/a/yr produced from 1984 to 1992 in the adjacent no-till crop-fallow system receiving 50 lb N/a. Application of 60 lb N/a each crop year or, based on regression analysis, an average available N supply (soil plus fertilizer N) of about 136 lb N/a was sufficient to optimize (95% of maximum) grain yields. Soil water use by crops and crop water-use-efficiency were increased by N fertilization (data not shown, Halvorson and Reule, 1 994b). Residual soil N03-N accumulation increased in the root zone at the 2 to 4 ft depth as N rate increased (data not shown, Halvorson and Reule, 1 994b). These results indicate potential for adopting more intensive dryland cropping systems in the Central Great Plains with adequate N fertilization.

Table 3. Crop yield as a function of N rate for each crop year in the annual cropping study at Akron, Colorado
			N Rate, lb/a
Year	Crop	Factor	0	20	40	60	80	120
1984	B	Yield, bu/a	48	70	69	77	76	65
1985	C	Yield,bu/a	66	75	96	101	97	106
1986	B	Yield, bu/a	8	22	38	44	53	59
1987	C	Yield, bu/a (hailed out)	0	0	0	0	0	0
1988	WW	Yield,bu/a	39	45	48	54	51	47
1989	C	Yield,bu/a	41	52	53	60	53	66
1990	B	Yield,bu/a	3	8	18	21	18	16
1991	C	Yield,bu/a	68	77	93	102	97	96
1992	OH	ForageYield,lb/a	654	1619	2742	3238	3908	4433
1993	C	Yield, bu/a	40	46	63	83	78	84
aB=spring barley; C=corn; WW=winter wheat; OH--oat hay

An economic analysis was performed for USDA-ARS by Drs. Norm Toman and Ray Anderson, Ag Economists with Colorado State University, based on the yield data reported in Table 3 to determine estimated returns per acre based on production and ownership costs for each crop year. The same production costs were used for machinery and custom rates as used in the economic analysis of the wheat-fallow system at Akron. Herbicide needs varied from year to year based on crop grown, length of fallow period between crops, and climatic conditions. Herbicide costs based on 1991 prices and 10 year average crop prices were used in the analysis, as well as, historic yearly crop and herbicide prices. Estimated returns over production and ownership costs are shown in Table 4 for each N rate when using 10 year average crop prices and 1991 herbicide and operational costs. No Farm Program deficiency payments were included in this analysis. Except for the oat hay in 1992, the application of 60 lb N/a each crop year generally resulted in highest dollar return per acre. Adequate N fertilization is needed to optimize economic returns in an annual cropping system. The highest average 10 yr return per acre ($44/a/yr) was obtained with the 60 lb N/a rate. If the loss encountered in 1987 due to hail is excluded, the 9 yr average return is increased to $58/a/yr for this annual cropping system.

Table 4. Estimated returns over production and ownership costs using a 10 year average fixed crop price and 1991 herbicide costs as a function of N rate for the annual cropping study at Akron Colorado.
		N Rate. lb N/a
Year	Crop	0	20	40	60	80	120
1984	B	$34	$67	$75	$70	$64	$24
1985	C	$78	$90	$132	$139	$125	$127
1986	B	($47)	($30)	($4)	$2	$14	$16
1987	C (hailed out)	($60)	($69)	($74)	($79)	($83)	($93)
1988	WW	$64	$76	$83	$100	$88	$70
1989	C	($7)	$17	$14	$25	$4	$24
1990	B	($46)	($46)	($32)	($31)	($42)	($55)
1991	C	$64	$76	$107	$123	$107	$95
1992	OH	($24)	($12)	$7	$13	$23	$24
1993	C	$2	$7	$41	$81	$65	$69
Total return for l0 yr, $/a		$58	$157	$350	$445	$365	$300
Avg return, $/yr		$6	$16	$35	$44	$36	$30
'B=spring barley; C=corn; WW--winter wheat; OH=oat hay

A ten year comparison is shown in Table 5 for the adjacent CT wheat-fallow rotation with 50 lb N/a each crop year and the annual cropping system with 60 lb N/a each crop year. The 1985 wheat-fallow rotation wheat crop was destroyed due to a severe infestation of jointed goatgrass, which resulted in an economic loss. The analysis in Table 5 included the yearly variation in wheat prices and deficiency payments for the wheat-fallow rotation based a 1200 acre farm with 600 acres of planted winter wheat. Farm Program deficiency payments were not considered or used in the annual cropping analysis, but yearly variation in crop price and herbicide costs were used to calculate economic returns. The 1991 machinery, production, and ownership costs were used in the analysis. As the data shows (Table 5), the annual cropping system, even with net losses in 1987, 1989, and 1990, had a higher ($44/a/yr) 10 year average annual return than the winter wheat-fallow rotation ($27/a/yr). If the 1985 wheat-fallow crop year and the 1987 hail loss in the annual cropping system (yield losses caused by external factors) are excluded from the analyses, the 9 year average net returns are $37/a/yr for wheat-fallow and $60/a/yr for annual cropping system. It is interesting to note that the 10 year average return per acre per year was the same for the annual cropping system in Table 4 (60 lb N/a) and Table 5. Using the 10 year average crop prices and the 1991 herbicide costs gave the same results as using crop and herbicide prices for individual years. The higher net return per acre with annual cropping and without government payments is very positive for those producers interested in more intensive cropping systems.

Table 5. Estimated yearly returns from conventional till, winter wheat-fallow with 50 lb N/a in comparison to the no-till annual cropping system with 60 lb N/a. Yearly crop and herbicide rices were used.
Year	CT Wheat-Fallow (50% cropped)		NT Annual Cropping System (100% Cropped)
	Yield	Return, $/a/yr	Crop	Yield	Return, $/a/yr
1984	41.0 bu/a	$34	Barley	77bu/a	$104
1985	Crop destroyed(a)	($61)	Corn	101bu/a	$127
1986	52.6 bu/a	$40	Barley	44bu/a	$34
1987	47.0 ba/a	$37	Corn	hailed out	($100)
1988	35.0 bu/a	$31	W.Wheat	54bu/a	$105
1989	29.0 ba/a	$16	Corn	60ba/a	($7)
1990	31.5 ba/a	$17	Barley	21ba/a	($13)
1991	56.0 bu/a	$66	Corn	102ba/a	$110
1992	38.0 ba/a	$26	Oatllay	1.6t/a	$13
1993	58.6 bu/a	$64	Corn	83bu/a	$63
Total return for 10 yr, $/a		$270	Total return for 10 yr, $/a		$436
Average return, $/a/yr		$27	Average return, $/a/yr		$44
a Crop destroyed because of a heavy infestation of jointed goatgrass in the winter wheat.

Tillage-N-Cropping System Study, Mandan, ND. The study involves two cropping systems (spring wheat-fallow and spring wheat-winter wheat-sunflower), three tillage Systems (CT, RT, NT, three N fertilizer levels (0, 20, 40 lb N/A for crop-fallow, and 30, 60 and 90 lb N/A for the 3-yr annual crop rotation) and two cultivars of each crop. The study was initiated in 1984 with the first yield data collected in 1985. Table 6 shows the grain yields for the spring wheat, winter wheat, and sunflower crops for each rotation averaged over crop cultivars. Spring wheat in annual cropping system has a 10-year average yield of 22.1 bu/a; winter wheat, 28.2 bu/a; and sunflower, 1288 lb/a. Spring wheat in the spring wheat-fallow rotation has a 10 year average annual yield of 16.4 bu/a/Yr or 32.7 bu/a each crop year (2 yr period).

Table 6. Ten-year (1985-1994) average annual crop yields in sp. wheat-fallow and sp. wheat-w.wheat-sunflower rotations as a function of tillage system and N-fertilizer level.
Crop (rotation)	N Fertilizer rate	Tillage system			N-fert. avg.
	lb N/a	bu/a
Sp. Wheat (W-F)	0	16.5	16.1	15.7	16.1
	20	17.0	16.3	15.7	16.3
	40	16.9	16.8	16.4	16.7
Tillage average		16.8	16.4	16.0	16.4
Sp. Wheat (annual crop)	30	19.3	21.6	19.9	20.3
	60	21.5	23.1	22.1	22.2
	90	21.8	24.6	25.2	23.9
Tillage average		20.8	23.1	22.4	22.1
W. Wheat (annual crop)	30	25.7	27.5	27.7	26.9
	60	26.3	29.2	30.4	28.6
	90	26.8	29.3	30.8	28.9
Tillage average		26.2	28.6	29.6	28.2
lb/a
Sunflower (annual crop)	30	1191	1257	1197	1215
	60	1246	1359	1272	1292
	90	1274	1368	1428	1357
Tillage average		1237	1328	1299	1288

Spring wheat yields in the wheat-fallow rotation decreased significantly as tillage intensity decreased when averaged over years. A significant increase in yield was observed with increasing N rate. Comparing annual spring wheat yields from wheat-fallow to spring wheat yields in continuous cropping reveals a 5.7 bu/a/yr yield advantage for continuous cropping. In the continuous cropping system, wheat yields increased with a decrease in tillage and with increasing N fertilizer rate. A significant tillage x N interaction for sunflower yields shows the advantage of NT at the highest N rate. Comparing the pounds of grain produced in a 6 year period with continuous cropping to wheat-fallow shows 5940 lb wheat produced for wheat-fallow vs 6036 lb wheat and 2576 lb sunflower for continuous crop. Thus total grain production is greater for the continuous cropping system than for wheat-fallow. These data agree with the data reported for the Colorado studies.

In 1991, Dwight Aakre, NDSU Extension Economist, conducted a partial economic analysis on the first 6 yr of data from this study (personal communications with Mr. Aakre). This included three years (1988, 1989, 1990) of extreme drought where wheat yields were less than 5 bu/a in 1998 and sunflower yields less than 100 lb/a in 1990. He considered returns over variable costs in this comparison for the medium N rate only. The partial budgets included only those inputs that may change from one system to another. Table 7 presents the average annual return over variable costs with conventional tillage as calculated by Mr. Aakre on the average yields for the first 6 yr (1985-1990). The authors used Mr. Aakre's analysis and budgets to calculate a 10 year return (Table 7) by substituting the 10 year average yields (1985-1994) for the 6 year average yields used by Mr. Aakre. The data show an economic advantage for annual cropping over wheat-fallow for both the 6 yr and lO yr analysis. In addition, Table 8 shows the average 6 yr return over variable costs for CT, RT, and NT tillage systems for wheat-fallow and continuous cropping. The economic advantage of continuous cropping are demonstrated in this preliminary economic analysis of the cropping systems. Again, as shown in the Colorado studies, there is little difference between tillage systems when using wheat-fallow.

The economic advantages to RT and NT become more apparent as cropping intensity is increased. One has to recognize that there is an increase in production costs and risk with a move to the more intensive cropping systems. But as with other investments, higher profit potential often is accompanied with higher risk. The benefits of NT and RT systems for storing precipitation more efficiently and reducing soil erosion potential can be realized with the potential for economic gain. The added benefits of increased crop residue on the soil surface with RT and NT will add to the soil organic matter and improve soil quality and fertility over the long term.

Table 7. Average annual return over variable costs with conventional tillage using yield data from 1985 to 1990 (6 yr) and from 1985-1994 (10 yr) from the USDA-ARS cropping system study at Mandan, ND.
Cropping System	1985-90 (6 yr)	1985-1994 (l0 yr)
Sp. Wheat - Fallow	$31.65	$35.62
Annual Crop (SW-WW-Sun)	$34.92	$45.31
Annual Crop Advantage	$3.27	$9.69

Table 8. Average annual return over variable costs per acre for each of the three tillage systems, CT, RT, and NT for 1985-90 (6 yr) for USDA-ARS cropping system at Mandan, ND.
Tillage System	Wheat-fallow	Annual Crop (SW-WW-Sun)
CT	$31.65	$34.92
RT	$30.88	$43.63
NT	$29.15	$42.96

REFERENCES

1. Dhuyvetter, K.C., C.R. Thompson, C.A. Norwood, A.D. Halvorson. 1995. Economics of Dryland Cropping Systems in The Great Plains: A Review. J. Production Agriculture (final revision after journal review submitted for publication)

2. Halvorson, A.D, and C.A. Reule. 1 994a. Nitrogen fertilizer requirements in an annual dryland cropping system. Agron. J. 86:315-318.

3. Halvorson, A.D., and C.A. Reule. 1994b. Nitrogen fertilizer effects on dryland crop yields, water use, and soil nitrogen. Great Plains Agric. Council Bulletin No.150. pg. 43-50.

4. Halvorson, A.D., R.L. Anderson, N.E. Toman, and J.R. Welsh. 1994. Economic comparison of three winter wheat-fallow systems. J. Production Ag. 7:381-385.

ACKNOWLEDGMENT

The author wants to thank the following persons for their contribution to the data and economic analyses used in this manuscript. Curtis Reule for collection and analysis of field data from the Colorado studies and Dr. Norm Toman and Dr. Ray Anderson, Ag Economists with Colorado State University, Fort Collins for their economic analyses of the cropping and tillage systems. Floyd Jacober, James Harms, Marvin Hatzenbuhler, Larry Renner, and Ron Vredenburg for collection and analysis of field data from the Mandan study and Dwight Aakre for the economic analyses of the cropping systems.