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© 2008 Plant Management Network. This article is in the public domain. Corn and Cotton Yield with Two Surface Drip Lateral Spacings Ronald B. Sorensen and Marshall C. Lamb, Research Agronomist and Research Economist, USDA-ARS-National Peanut Research Laboratory, PO Box 509, 1011 Forrester Dr. SE, Dawson, GA 39842 Corresponding author: Ronald B. Sorensen. ron.sorensen@ars.usda.gov Sorensen, R. B., and Lamb, M. C. 2008. Corn and cotton yield with two surface drip lateral spacings. Online. Crop Management doi:10.1094/CM-2008-0118-01-RS. Abstract Surface drip irrigation laterals were spaced next to crop rows (0.91 m) and in alternate row middles (1.83 m) to document crop yield and partial economic returns compared with non-irrigated areas. A surface drip irrigation system was installed at two sites on a Faceville (Site 1) and a Greenville (Site 2) fine sandy loam with 1 to 3% slope, respectively. Cotton and corn were planted on 0.91-m row spacing. Drip tube orientations, 0.91 and 1.83 m, had the same corn yield (10,555 kg/ha) compared with the non-irrigated areas (5,562 kg/ha). Subtracting the cost of corn seed and drip tubing from the two irrigated regimens show that 0.91-m lateral spacing had $140/ha less net revenue compared with non-irrigated ($484/ha). The 1.83-m spaced laterals had $196/ha greater net revenue than the non-irrigated areas. Cotton lint yield averaged 1194 kg/ha for 0.91 and 1.83-m lateral spacing compared with the non-irrigated lint yield (608 kg/ha). Cotton gross revenue at both sites averaged about $1200/ha for both lateral orientations. Non-irrigated cotton revenue averaged over $600/ha. Subtracting the cost of the tubing resulted in net revenues of $613 and $969 for 0.91 and 1.83-m lateral spacing, respectively. The 0.91-m lateral spacing may not be cost effective for either corn or cotton. Partial net return analysis shows that 1.83-m lateral spacing had higher returns for both crops. Introduction Surface drip irrigation, due to its simplicity, has been used to irrigate vegetables and high value crops for many years (3,14). These systems precisely deliver water, nutrients, and chemicals to the crop root zone. One of the greatest advantages of using surface drip irrigation is that the system can be installed easily with low initial investment and provide flexible irrigation schedules without using large pumps and wells. Researchers have shown that surface (SDI) and subsurface drip irrigation (SSDI) are effective on many crops, locations, and environmental conditions using various techniques (3,9,13,14,16,23). Due to the increases in irrigated corn and cotton hectares, research efforts have addressed optimal timing and irrigation methods to suit regional production demands (10,17,20,26,27). Subsurface drip irrigation (SSDI) on peanut in the humid southeast has been effective in increasing pod yield and grade specifically kernel size distribution (24) when compared with non-irrigated peanut production (17). Various researchers have shown that SSDI can increase crop yield and quality on tomato (Lycopersicon esculentum) (1,6), cotton (Gossypium hirsutum) (5,15), and corn (Zea mays) (22). Potential advantages of drip irrigation include the beneficial use of water, enhanced plant growth and yield, improved application of fertilizer, reduced weed growth, and decreased energy requirements (4). Drip irrigation can contribute to maximizing water use efficiency with negligible soil evaporation, percolation, and runoff (21). Economic simulations (2) showed that SSDI would be more profitable for small areas (< 30 ha) because of its lower investment per unit land area and lower pumping costs compared to fixed or towable center-pivot systems. Subsurface drip irrigation is also suited to irregularly sized fields where a full circle irrigation system cannot be installed. These areas often require drip irrigation to provide sufficient water to different field areas according to the area and crop species. There is little research done on the use of surface drip irrigation in corn or cotton production and the effects on yield (27). In addition, there is little information on the economic feasibility of surface drip technology on corn or cotton production and the transfer of this information to the grower. The objectives of this research were to: (i) show cotton and corn yield response to surface drip irrigation with two lateral spacings, and (ii) provide an economic analysis of surface drip irrigation versus non-irrigation. Measuring and Evaluating Response to Surface Drip Irrigation This research was conducted at the USDA-ARS Multi-crop Irrigation Research Farm in Shellman, GA (18) during the 2002, 2003, and 2004 growing season. There were two sites, two drip tube lateral spacings, and a non-irrigated control. Site 1 was a Faceville fine sandy loam (fine, kaolinitic, thermic Typic Kandiudults) with up to 3% slope. Topography was undulating with a general slope towards the east with a north aspect. Site 2 soil type was a Greenville fine sandy loam (fine, kaolinitic, thermic Rhodic Kandiudults) with slopes less than 1%. At Site 1, three areas were selected for crop rotations of cotton, corn, and peanut. Each crop rotation was 60 m wide by 91.2 m long. Each area was split into irrigated and non-irrigated regimen. Irrigated treatments included drip tube laterals spaced at 0.91 m (next to a crop row) and 1.83 m (alternate row middles) in a complete randomized block design. Individual plots were 5.5 m wide and 91.2 m long separated into six individual subplots or positions (15.2 m long) used to help identify yield versus slope interaction. Non-planted beds were used as travel rows so that once the drip tubing was installed no wheeled traffic was allowed in the plots until harvest (27). Site 2 is part of a long term crop rotation and irrigation system project where part of a non-irrigated area was irrigated using surface drip tubing (18). The overall project was a randomized complete block design with six crop rotations, three irrigation designs (subsurface drip, surface drip, and overhead sprinkler) with a non-irrigated control. Each non-irrigated subplot was 18 rows wide (0.91-m row spacing) and 61 m long. This report will only consider the surface drip irrigation and non-irrigated areas of this long term project. Land preparation was the same for both sites, all rotations, and for each year. The land was disk harrowed, deep ripped and then bottom plowed in late spring or early fall depending on weather conditions. Lime was applied in early spring at rates determined by soil test. In the spring a field cultivator was used for weed control and soil amendment incorporation. Preplant incorporate herbicides were selected by potential weed problem and incorporated according to labeled rates and timing designated by the manufacturer. During the growing season, contact herbicides were selected and applied by weed spectrum and crop characteristics. Corn cultivar was DK687 in 2002 and DK697 in 2003 and 2004 at Site 1. At Site 2, the corn cultivars were DK687 in 2002 and 2003 and DK6972RR in 2004. Cotton cultivar was DPL 458 for both sites in 2002 and 2003. In 2004, the cotton cultivar at both sites was DPL 555. All years and crops were planted with a commercial vacuum type planter (Monosem planter, ATI Inc, Lenexa, KS). Crop row spacing was set at 0.91 m with seeding rate of 76,600 and 47,000 seeds/ha for irrigated and non-irrigated, respectively. Irrigated and non-irrigated cotton were planted at the same rate of 136,000 seeds/ha. Irrigation water was supplied through a series of 5-cm diameter flexible hose with drip tubing connected using adapters containing shutoff valves (model 400-BV-06-LS, Agricultural Products, Inc., Ontario, CA). The drip tubing had 0.2-mm wall thickness with emitters spaced at 30 cm (Roberts Irrigation Products, Inc., San Marcos, CA). The 0.91-m spaced lateral was about 5 cm away from the crop row. The 1.83-m spaced laterals were spaced in alternate row middles. Emitter flow rate was 0.91 liter/h (2002) and 0.56 liter/h (2003 and 2004). Operating pressure was 70 kPa at the head of the field (100 kPa at the pump) and water flow was measured with a mechanical water meter. Research with subsurface drip irrigation has shown a water savings of about 25% without loss of yield or grade for cotton, corn, and peanut (25) when compared with literature values for overhead irrigation systems. Irrigation events were determined by decision support system, IrrigatorPro (11) for cotton and corn which was developed for overhead sprinkler systems. Therefore, irrigation depths for surface drip values were reduced by an average 18% less than recommended for sprinkler applications. Both lateral spacings received the same amount of water. Thus, irrigation depths were closer to the 25% described previously (25). Precipitation data were collected with an electronic weather station located onsite and verified with a manual precipitation gauge. All treatments were harvested when mature. Corn was harvested with a 4-row combine. Each sample was weighed using a weigh buggy. A 2-kg subsample was collected after the transfer of corn from the combine to the weigh buggy. Each sub-sample was tested for moisture and density. Cotton was picked using a 2-row spindle picker. The picker was modified to collect cotton in a large mesh bag. The sample was weighed and ginned. A 0.1 kg sub-sample was collected from each ginned sample to determine lint quality. Gross revenue was determined from crop yield, grade, and price. Crop prices were averaged over the project life (2002 to 2004). Corn price averaged $0.0964/kg and cotton price averaged $1.09/kg (12). Partial net revenue was calculated by subtracting the cost of the drip tubing from the gross revenue. It was assumed that all other major costs, such as, fuel, fertilizer, pesticide, and land costs are equal across both lateral spacings. Current recommendations suggest that non-irrigated corn be planted with about 40% less seed compared with irrigated areas. Therefore, corn seed cost $52/ha for non-irrigated and $86/ha for irrigated corn production. Data from each site were analyzed independently. Crop yield and grade parameters along with gross revenue were analyzed using linear models with a general analysis of variance procedure (Statistix 8, Analytical Software, Tallahassee, FL) with respect to year and lateral spacing. Differences between means were determined using the Tukey method at the P ≤ 0.05 level when ANOVA F-test showed significance. Corn Yield and Economics Precipitation received, water applied, and plant and harvest dates are shown in Table 1. Cumulative precipitation was highest in 2003 for corn and 2002 for cotton. Higher precipitation values do not always mean less cumulative irrigation. In southwest Georgia convective thunderstorms tend to be high intensity and short duration such that total precipitation can be much greater than cumulative plant transpiration. Time periods between convective thunderstorm events are variable with either short or long time periods between events. The results of these precipitation patterns are wet or drought periods between events that require little or greater applications of irrigation water. Differences in irrigation values between sites are due to soil type and precipitation timing. Both sites could not be irrigated at the same time due to pump capacity restrictions. Therefore, one site could be irrigated and a precipitation event occurred before an irrigation event could occur on the second site. Thus, year to year variations for irrigation amounts and precipitation are expected. Table 1. Precipitation, irrigation, planting, and harvest dates documented for corn and cotton, respectively, 2002 to 2004. Cumulative precipitation for corn was through 01 March to 15 August while cotton was through 01 May to 30 September.
Corn was planted in late March to early April with harvest times in mid August. Corn yield at Site 1 showed no difference between years but did show yield difference with drip tube lateral spacing (non-irrigated areas were included in tubing analysis) (Table 2). Irrigated corn grain yield averaged 10,957 kg/ha across all years, 2002 to 2004. Corn yield showed no difference between the 0.91-m and 1.83-m drip tube orientation. Both lateral spacings had higher yield than the non-irrigated control. Revenue was higher for the irrigated compared with the non-irrigated areas. Table 2. Corn ANOVA probability values for yield, test weight, and gross
revenue determined for year and lateral spacing. Corn yield, test weight,
* Means followed by the same lower-case letter are not significantly
** Partial net revenue = (gross revenue – drip tube cost).
Corn yield at Site 2 was affected by year and by lateral spacing (Table 3). Corn yield for 2003 and 2004 was the same (9996 kg/ha) but different than 2002 (6670 kg/ha). Drip tube orientations, 0.91 and 1.83 m, had higher corn yield (10,555 kg/ha) compared with the non-irrigated areas (5,562 kg/ha). Gross revenue was higher for the irrigated versus the non-irrigated areas. Previous research has shown that subsurface drip irrigation laterals spaced in row middles have the same yield as those placed underneath the crop rows (19,22). Table 3. Corn ANOVA probability values for yield, test weight, moisture,
* Means followed by the same lower-case letter are not significantly
** Partial net revenue = (gross revenue – drip tube cost).
The 0.91-m drip tube lateral spacing cost about $540/ha just for the tubing. Subtract the cost of the tubing (0.91-m lateral spacing) from the average gross revenue (average of both Site 1 and 2) shows a negative return of $-108 compared with the non-irrigated return. The cost of tubing for the 1.83-m lateral orientation was half of the 0.91-m lateral spacing resulting in a $231/ha net increase in returns compared with the non-irrigated area (average of both Site 1 and 2). Another savings for the non-irrigated areas was in the cost of seed. Subtracting both tubing and seed cost from the two irrigated regimens (average of both Site 1 and 2) show that 0.91-m lateral had a negative $-142 return compared with non-irrigated ($484/ha). The 1.83-m spaced laterals had a positive $196/ha greater net revenue compared with the non-irrigated areas after subtracting drip tubing and corn seed costs. Corn research in western Kansas showed that subsurface drip laterals placed in alternate row middles were more cost effective than laterals placed beneath the crop row (19,22). Average corn grain yield in Georgia for non-irrigated areas (1998 to 2005) was 4582 kg/ha (12). Two of the highest corn yields were in 2003 and 2004 (12). If we removed the higher yielding years from the state average, the new average corn grain yield would be 3061 kg/ha which may better reflect normal non-irrigated yields. Using this lower non-irrigated corn grain average value, net revenue for the 1.83-m lateral spaced irrigation would increase to $456/ha greater than the average non-irrigated revenue($243/ha, seed cost subtracted). Using the lower state corn grain average would result with positive net revenue of $117/ha for the 0.91-m lateral spacing. Cotton Yield and Economics Cotton was planted in late April to early May with harvest in October or November. Both yield and gross revenue were affected by year and by lateral spacing at Site 1 (Table 4). Site 1 cotton lint yield was different each year. The 0.91- and 1.83-m lateral spacing had the same lint yield averaging 1141 kg/ha compared with the non-irrigated lint yield (586 kg/ha). Gross revenue for the irrigated areas was almost two times that of non-irrigated areas. Table 4. Cotton ANOVA probability values for lint yield, and gross revenue
* Means followed by the same lower-case letter are not significantly
** Partial net revenue = (gross revenue – drip tube cost). Site 2 cotton lint yields and revenue were different by year and lateral spacing (non-irrigated plots were part of this analysis) (Table 5). There was no difference in lint yield for 2003 and 2004 but were greater than lint yields in 2002 by about 40%. Both the 0.9 and 1.83-m tube lateral orientations had the same lint yield (1052 kg/ha) but was higher than the average non-irrigated control (455 kg/ha). Gross revenue was almost 50% greater with irrigation compared with non-irrigation. These results are similar to those described in previous research with subsurface drip tube laterals placed underneath crop rows did not have higher yield than laterals placed in alternate row middles (7,8,22). Table 5. Cotton ANOVA probability values for lint yield, and gross
* Means followed by the same lower-case letter are not significantly
** Partial net revenue = (gross revenue – drip tube cost).
Site 1 and Site 2 gross revenue averaged about $1200/ha for both lateral spacings. Non-irrigated gross revenue averaged just over $600/ha. Subtracting the cost of the tubing resulted in net revenues of $613 and $969 for 0.91 and 1.83-m lateral spacing, respectively. The non-irrigated revenue was very similar to the 0.91-m lateral spacing while the 1.83-m lateral spacing was over $360/ha greater than the non-irrigated control. This implies a lateral spacing of 0.91 m may not be cost effective even when lint yields are doubled with irrigation and that alternate row middles are recommended for higher yields and net returns (2,7,8,22). Conclusions Surface drip irrigation doubled corn and cotton yield compared with non-irrigated regimes. There was no yield difference between drip tube lateral spacings for either crop. Subtracting the cost of seed (corn only) and tubing showed that 0.91-m lateral spacing had equal to (cotton) or negative (corn) net returns compared with non-irrigated production. The 1.83-m lateral spacing had positive net returns for both crops and years. Both drip tube lateral orientations had positive net returns when compared with non-irrigated yields that were near the state average. When irrigating corn and cotton with surface drip in the southeast it is recommended that drip laterals be installed in alternate row middles for best economic net return. Acknowledgments The authors would like to thank Jesse Childre and Ernest Yoder for field layout, drip tube installation, day-to-day maintenance, and yield data collection and analysis. Mention of proprietary product or company is included for the reader’s convenience and does not imply any endorsement or preferential treatment by the USDA-ARS. Literature Cited 1. Bogle, C. R., Hartz, T. K., and Nunez, C. 1989. Comparison of subsurface trickle and furrow irrigation on plastic-mulched and bare soil for tomato production. J. Am. Soc. Hort. Sci. 114:40-43. 2. Bosch, D. J., Powell, N. L., and Wright, F. S. 1992. Investment returns from three sub-surface microirrigation tubing spacings. J. Prod. Agric. 11:371-376. 3. Bucks, D. A., Erie, L. J., and French, O. F. 1974. Quantity and frequency of trickle and furrow irrigation for efficient cabbage production. Agron. J. 66:53-57. 4. Bucks, D. A., and Davis, S. 1986. Historical development. Pages 1-26 in: Trickle Irrigation for Crop Production. F. S. Nakayama and D. A. Bucks, eds. Elsevier, New York, NY. 5. Bucks, D. A., Allen, S. G., Roth, R. L., and Gardner, B. R. 1988. Short staple cotton under micro and level-basin irrigation methods. Irrig. Sci. 9:161-176. 6. Camp, C. R., Sadler, E. J., and Busscher, W. J. 1989. Subsurface and alternate-middle microirrigation for the southeastern coastal plain. Trans. ASAE 31:451-456. 7. Camp, C. R., Thomas, W. M., and Green, C. C. 1993. Microirrigation scheduling and tube placement for cotton in the southeast coastal plain. ASAE 36:1073-1078. 8. Camp, C. R., Bauer, P. J., and Hunt, P. G. 1997. Subsurface drip irrigation lateral spacing and management for cotton in the southeastern coastal plain. ASAE 40:993-999. 9. Camp, C. R. 1998. Subsurface drip irrigation: A review. Trans. ASAE 41:1353-1367. 10. Davidson, J. I., Jr., Bennett, C. T., Tyson, T. W., Baldwin, J. A., Beasley, J. P., Bader, M. J., and Tyson, A. W. 1998. Peanut irrigation management using EXNUT and MOISNUT computer programs. Peanut Sci. 25:103-110. 11. Davidson, J. I., Jr., Lamb, M. C., and Sternitzke, D. A. 2000. Farm suite – Irrigator Pro (Peanut irrigation software and users guide). The Peanut Foundation, Alexandria,VA. 13. Goldberg, D., and Shmueli, M. 1970. Drip irrigation - a method used under arid and desert conditions of high water and soil salinity. Trans. ASAE, 13:38-41. 14. Hanson, B. R., Schwanki, L. J., Schulbach, K. F., and Pettygrove, G. S. 1997. A comparison of furrow, surface drip, and subsurface drip irrigation on lettuce yield and applied water. Agric. Water Manag. 33:139-157. 15. Henggeler, J. C. 1988. Drip irrigation: Lowering installation costs, increasing yields and improving water-use efficiency. Pages 31-32 in: Proc. 1988 Highlights of cotton production Res. Conf., Special Sessions: New Developments from Industry. 3-8 Jan. 1988, New Orleans. J. M. Brown and D. Richter, ed. Natl. Cotton Council of America, Memphis, TN. 16. Hodgson, A. S., Constable, G. A., Duddy, G. R., and Daniells, I. G. 1990. A comparison of drip and furrow irrigated cotton on a cracking clay soil. Water use efficiency, waterlogging, root distribution and soil structure. Irrig. Sci. 11:143-148. 17. Lamb, M. C., Davidson, J. I., Jr., Childre, J. W., and Martin, N. R., Jr. 1997. Comparison of peanut yield, quality, and net returns between nonirrigated and irrigated production. Peanut Sci. 24:97-101. 18. Lamb, M. C., Rowland, D. L., Sorensen, R. B., Zhu, H., Blankenship, P. D., and Butts C. L. 2003. Research at the NPRL Shellman irrigated research farm. Am. Peanut Res. Ed. Soc. Abstr. Vol. 35. 19. Lamm, F. R., Stone, L. R., Manges, H. L., and O’Brien, D. M. 1997. Optimum lateral spacing for subsurface drip irrigated corn. Trans. ASAE 40:1021-1027 20. Pahalan, D. K., and Trapathi, R. S. 1984. Irrigation scheduling based on evaporation and crop water requirement for summer peanuts. Peanut Sci. 11:4-6. 21. Phene, C. J., Hutmacher, R. B., El Ayars, J., Davis, K. R., Mead, R. M., and Schoneman, R. A. 1992. Maximizing water use efficiency with subsurface drip irrigation. ASAE Paper No. 92-2090. St. Joseph, Mich.: ASAE. 22. Powell, N. L., and Wright, F. S. 1993. Grain yield of subsurface microirrigated corn as affected by irrigation line spacing. Agron. J. 85:1164-1170. 23. Sammis, T. 1980. Comparison of sprinkler, trickle, subsurface, and furrow irrigation methods for row crops. Agron. J. 72:701-704. 24. Sorensen, R. B., Wright, F. S., and Butts, C. L. 2000. Pod yield and kernel size distribution of peanut produced using subsurface drip irrigation. Appl. Engin. Agric. 17:165-169. 25. Sorensen, R. B., Butts, C. L., and Rowland, D. L. 2005. Five years of subsurface drip irrigation on peanut: What have we learned? Peanut Sci. 32:14-19 . 26. Wright, F. S., and Adamsen, F. J. 1993. Peanut and corn yield response to subirrigation through an existing drainage system. Appl. Eng. Agric. 9:55-60. 27. Zhu, H., Lamb, M. C., Butts, C. L., and Blankenship, P. D. 2004. Improving peanut yield and grade with surface drip irrigation in undulating fields. Trans. ASAE 47:99-106. |
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