Fuel savings with a new one-pass tillage machine, above, were an average of 50% better than with the conventional method tested. Time savings ranged from 67% to 83%, and soil aggregate sizes after tillage did not differ. One-pass tillage equipment outstrips conventional tillage method

Shrinivasa K. Upadhyaya cl Kleber P. Lancas u Abilio G. Santos-Filho LI Narendra S. Raghuwanshi

For this study, we compared a fficient farm management has al- rameters is an attractive option. new one-pass tillage implement E ways been of prime importance to Land preparation prior to planting called the lncorpramaster with a farmers, but large increases in capital generally requires significant energy conventional tillage practice of and operating costs in recent years inputs, resulting in high operating stubble disking and land planing. have made it even more important. costs; new techniques to reduce the Our randomized block experiment Farmers must find ways to maximize cost of preparing land could be ben- their net returns so they can operate eficial to growers. on the UC Davis campus evalu- within existing economic constraints Incorpramaster, Inc. of Modesto de- ated the equipment’s energy and and respond to growing environmen- veloped the Incorpramaster, a new time savings. We found that the tal concerns such as water quality and one-pass tillage implement, which in- one-pass tillage equipment particulate matter emissions. Nearly corporates several important tillage (OPTE) outperformed conven- 13.4 trillion British thermal units (Btu) operations into one machine. The ma- tional land preparation methods in of energy is expended in tillage opera- chine we tested was a prototype. The fuel consumption and speed. Fuel tions in California; almost all of this manufacturer reports that it should be savings ranged from 19% to 81% energy is derived from diesel fuel commercially available in coming with a mean savings of 50%. Time (Torgerson et al. 1987). months; we are unaware of any other savings ranged from 67% to 83% Greater farm profits can be similar equipment on the market. with mean of 72%. The mean soil achieved through increased returns The manufacturer claims that one particle size created by the one- or decreased costs. Producing higher or two operations using this device pass tillage implement was com- value crops depends on factors over can replace many operations com- parable to that produced by con- which growers have little control, monly employed with conventional ventional tillage methods. such as climate and market demand. farming methods. In row-crop produc- Improved varieties, fertilization, irri- tion in the Sacramento Valley, this gation and management have sub- typically includes two passes with a stantially increased production, but stubble disk and two passes with a these changes occur more slowly. Ex- land plane. panding acreage is one way to in- We compared the performance of crease total profit, but land con- the Incorpramaster one-pass tillage straints and market conditions often equipment (OPTE) with that of typi- prohibit this option. cal conventional tillage methods, in Therefore, reducing costs without terms of speed, energy savings and changing any other production pa- soil compaction.

44 CALIFORNIA AGRICULTURE, VOLUME 55, NUMBER 5 Conservation tillage Due to growing concerns about the impact of agricultural production on the environment, conservation tillage has increased over the past few de- cades. Conservation tillage uses new and proven techniques to reduce soil erosion, conserve moisture arid soil structure, reduce energy inputs and production costs, improve land use and reduce labor (Rask et al. 1967; McClure et al. 1968). Conservation till- age attempts to reduce primary soil tillage operations such as plowing, rip- ping, disking and chiseling, and dedi- cates tractor traffic to zones away from growing crops (Carter 1995). As a re- sult of deliberate reduction in tractor Field tests at UC Davis Dyna drive unit. According to the operations, growers may save energy, In 1998, we conducted tests on four manufacturer, the dyna drive unit produce less dust and sequester more experimental fields (plant pathology, consists of two mechanically linked carbon into the soil. Uri (1999) reported pomology, agricultural practices and rollers, with a gear ratio of 1:3 be- that the amount of land planted using agronomy) at UC Davis. The soil tex- tween the first and second rolls. The conservation tillage in the United ture at these four locations was Yolo first roll is ground-driven and in turn States increased from 1%1in 1963 to fine sandy loam, Brentwood silt loam, drives the second unit. The main pur- 37% in 1997. Yolo loam and Yolo silt loam, respec- pose of this unit is to loosen soil, break According to the Conservation tively. Our attempts to include a clods and mix stubble or pre-emergent Technology Information Center Capay clay field, the typical soil fertilizer. (Towery 1998), conservation tillage can farmed in the Sacramento Valley, Spiral reels roller. The spiral reels save as much as 225 hours and 1,750 were not successful; that field lacked roller is a ground-driven unit, 18 gallons of fuel per year on just 500 ag- adequate soil moisture for our field inches in diameter, which chops ricultural acres. Fewer trips through work. We selected a randomized stubble, breaks clods and mixes soil the field also saves an estimated $2,500 complete-block experimental design or pre-emergent fertilizer. This unit in machinery wear. While this enables with four blocks, one at each test site. is especially important as it prevents growers to farm more profitability, the We divided each block into two plots long stubble from clogging the fol- biggest gain may be the cumulative in- and randomly assigned one-pass tillage lowing rows of S-tines. crease in soil organic matter. equipment (OPTE) or conventional till- Chisel unit. A chisel unit with Nonetheless, less than 0.3'L of an- age to each. The plot sizes were 2.3,2.6, four rows of one-half-inch S-tines nual row-crop acreage in California's 4.6 and 3.7 acres at the plant pathology, with 7-inch sweeps provides deep Central Valley is currently farmed us- pomology, agricultural practices and tillage (beyond the normal plowing ing these practices; however, higher agronomy experimental field sites, re- zone), uniformly mixes soil by elimi- energy costs have spurred new interest spectively. All plots were previously nating rhizomes, and creates a con- in conservation tillage among Califor- tilled to a depth of 18 inches with a sistent seedbed. nia growers (Mitchell et al. 2000). Con- subsoiler, a common practice in row- Rolling harrows. Two rows of ventional crop production requires crop production in this area. We oper- 14-inch rolling harrows follow the nine to 11 tillage operations for pre- ated the subsoiler at 45 degrees to the S-tines. The pressure on these har- plant field preparation at 18% to 24% length of the plot during the first pass. rows can be easily adjusted for vary- of total production cost (Mitchell et al. During the second pass we operated the ing soil conditions using hydraulic 2000). Carter (1998,1985) and Carter et subsoiler at right angles to the direction cylinders. They also break clods and al. (1991) confirmed the potential to of the first pass. create a level seedbed. eliminate deep tillage and decrease the Ring roller. A 9-inch ring roller number of soil preparation operations Tillage equipment on a 7.5-inch tube provides a by as much as 60'%,.Conservation- or The OPTE is a large machine, 41 smooth, finished seedbed. The rings reduced-tillage practices have the po- feet long and 18 feet wide, and con- break clods and seal moisture and/or tential to reduce energy and labor costs sists of five tillage tool sets from front pre-emergent fertilizer. We operated in California agriculture, and in turn to back, allowing several operations to the OPTE using a 385-horsepower, total production costs and negative en- take place during each pass on the four-wheel-drive John Deere 8870 vironmental impacts. field (fig. 1). tractor. The OPTE's tillage depth

CALIFORNIA AGRICULTURE. SEPTEMBER-OCTOBER 2001 45 varied from 6 to 8 inches depending order to measure fuel levels, we on the initial soil moisture. parked the tractor at the same location In the Sacramento Valley, a typical in each field, before and after each test. conventional tillage method for row We measured the amount of fuel crops consists of two passes with a needed to return the manometer fuel stubble disk followed by two passes level to where it was before the test by with a land plane. This is a typical till- weighing an external fuel tank. age system for a row-crop production To determine the average speed of system in the Sacramento Valley. We operation, we measured the time re- used a 180-horsepower John Deere quired to travel 200 feet along a 4840 tractor for disking and planing straight line, 10 times for each treat- operations. The stubble disk had an ment. Also, for each tillage treatment operating width of 12 feet and a depth we took 10 measurements of cone in- of 6 to 8 inches. The land plane had an dex values before and after using a hy- operating width of 16.2 feet and a draulically operated, instrumented depth of 1 to 2 inches. cone penetrometer installed on a John Deere 2010 tractor. Field measurements In order to determine the aggregate We measured fuel consumption size distribution, we obtained five soil used the oven-dry method to deter- and forward speed during field tests samples in each plot before and after mine the bulk density and moisture and subsequently estimated the en- every test. We analyzed these samples content. Three more core samples ergy requirements and performance using a standard set of 3-inch, 1-inch, were taken after each test to obtain of both treatments. We also obtained 3/8-inch, No. 4,10,20,60 and 100 the final bulk-density and moisture- data on cone index, soil density and sieves and a mechanical shaker to de- content data in each plot. moisture content to quantify the ef- termine the fraction retained on each fect of each treatment on soil com- sieve. We used these fractions to deter- Evaluating the tillage paction. (Cone index refers to pen- mine the geometric mean diameter of Fuel consumption. An analysis of etration resistance of the soil, and is soil aggregates. The procedure used variance (ANOVA) based on a ran- measured using an American Society for finding geometric mean diameter domized block design showed that the of Agricultural Engineers [ASAE] was a modification of the method for OPTE required a significantly lower standard cone - 30" cone with determining fineness of feed materials amount of fuel (tables 1 and 2). The 0.5-square-inch base, operated at reported in ASAE Standard S319. We savings ranged from 19% to 81% with 72 inches/minute.) We used tillage also took photographs of experimental a mean of 50%. We attributed the po- depth, clod samples and photographs plots to visually evaluate the final soil mology field's higher fuel savings to to evaluate the final soil condition. condition. However, this technique the fact that only one pass of the OPTE We designed and fabricated a spe- turned out to be unreliable, as the ef- was necessary to create a soil condi- cial device consisting of a fuel pump fect of each treatment extended to the tion comparable to that of the conven- powered by the tractor battery, two full operating depth rather than just tional method; two passes of the OPTE 2-way valves and a graduated plastic the surface. were needed in all other test sites. tube to determine the exact fuel con- Using a volumetric core ring, we Speed. We adjusted the time re- sumption of each method (fig. 2). In took five soil samples in each plot and quired for stubble disking when the John Deere 8870 tractor was used in- stead of the John Deere 4840. The 8870 was used for operating the OPTE, in order to handle its 18-foot stubble disk rather than the 12-foot disk used with the 4840. The results indicated that the OPTE requires significantly less time compared with the conventional till- age method (tables 1 and 2). The speed advantage for the OPTE ranged from 67% to 83% with a mean of 72%. Cone index values. Mean cone in- dex values did not differ significantly before or after tillage. However, the mean cone index value in the tilled layer was significantly higher for OPTE than conventional tillage

46 CALIFORNIA AGRICULTURE, VOLUME 55, NUMBER 5 (table 3). The mean cone index value in significantly differ in the test plots (table the plots tilled by the OPTE was 179 2). Therefore, we felt it was unnecessary pounds per square inch (psi) com- to correct fuel consumption values for S.K. Upadhyaya is Professor, K. P.Lancas is pared with 114 psi in conventionally the respective depths of operation. Visiting Professor and A.G. Santos-Filho is tilled plots. These cone index values Aggregate size analysis. The Visiting Scholar, Department of Biological were not a concern in the dry soil con- ANOVA indicated that the mean ag- and Agricultural Engineering, UC Davis; ditions prevalent during our tests. In gregate size did not differ in the plots N.S. Raghuwanshi is Assistant Professor, wet conditions, however, the pressure before (initial conditions) or after till- Agricultural and Food Engineering, Indian in the hydraulic cylinders controlling age (table 2), demonstrating that both Institute of Technology, Kharagpur, India. the rolling harrows of the OPTE may treatments resulted in similar soil con- This study was supported by the Agricul- need to be set to lower values. ditions. tiiral Energy Assistance Program (Contract Density and moisture content. No. 400-92-09) ofthe California Energy Neither the initial nor the final density Time and fuel savings Commission. The authors thank Ricado or moisture content data significantly Based on our field tests at UC Amon of the California Energy Commission differed between the two tillage prac- Davis, we found that the one-pass till- for his interest. The mention of a trade name tices, indicating that the soil condition age equipment outperformed the con- is not intended as an endorsement of this or was uniform to start with and both ventional land-preparation method of similar products by the researchers or UC practices resulted in similar soil condi- stubble disking and land planing in Davis. tions after treatment (table 3).A loamy fields. Fuel energy savings slightly higher moisture content was ranged from 19% to 81% with a mean References observed in most of the plots after till- savings of 50%. Time savings ranged Carter LM. 1985. Wheel traffic is costly. age for both treatments because moist from 67% to 83% with a mean of 72%. Trans ASAE 28(2):430-4. soil from beneath mixed with the dry Mean aggregate size created by the Carter LM. 1998. Tillage in Cotton Produc- surface soil. OPTE was comparable to that pro- tion. UC DANR Pub P1-14, Oakland, CA. 14 p. Operating depth. The ANOVA duced by the conventional tillage Carter LM, Meek BD, Rechel EA. 1991. Zone production for cotton: Soil response. showed that the operating depth did not method. Trans ASAE 34(2):354-60. McClure WR, Phillips SH, Herron JW. 1968. No-tillage experiences in Kentucky. St. Joseph, MI: ASAE Paper No 68-144. Mitchell JP, Lanini WT, Temple SR, et al. 2000. Conservation tillage initiatives in Cali- fornia. In: Proc of Conservation Tillage 2000: Conservation Tillage Success Stories from around the US, Feb 10-1 1, Davis, CA. UC Davis. 83 p. Rask N, Triplett GB, van Doren DM. 1967. A cost analysis of no-tillage corn. Ohio Report 52( 1):14. Torgerson D, Duncan J, Dorgan A. 1987. Energy in US Agriculture. USDA Natural Re- sources Economic Division, Washington, DC. 8 p. Towery D. 1998. Conservation tillage re- port “troubling” for US agriculture. Conserva- tion Technology Information Center news re- lease; Nov. 4, 1998. http://www.ctic.purdue .edu/Core4/CT/ctsurvey/AgTroubling. html Uri ND. 1999. Energy and the use of con- servation tillage in US agriculture. J Energy Fig. 2. Schematic of the fuel consumption measurement system used in this study. Policy 27:299-306.

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