| Title |
Investigators | Department | Objectives | Approach Keywords | Progress Reports | Impact Statements | Publications | |
Project * COL00654 | |
| Title | Crop Management and Sorghum Improvement |
| Investigator(s) | Larson, KJ; Berrada, A; Thompson, DL; |
| Department | Soil and Crop Sciences |
| Objectives | Increase yields and grower profitability, improve quality and enhance overall management of crops in S.E. Colorado, especially grain and forage sorghum, by cultural practices and physiological methods. |
| Approach | Determine yields and profitability of hybrids, irrigation methods, plant density, row spacing, planting date, crop rotations, fertilization, weed control, and tillage systems under various climatic and edaphic conditions. |
| Keywords | Sorghum Hybrids, Irrigation Methods, Plant Density, Row Spacing, Planting Date, Crop Rotations, Fertilization, Weed Control, Tillage Systems, Crop Management |
| Progress Reports | |
| 1993 | In our Grain Sorghum Hybrid Performance Tests we evaluate the typical parameters of yield, test weight, plant height, harvest density, lodging, days to half bloom. In response to grower requests for better comprehension of grain sorghum hybrid yield differences between sites and years, we included: growing degree days, days to maturation, days to emerge, growing season precipitation and temperature, available soil water, and soil analysis. To further aid growers in their hybrid selection, we added maturity group classification. Selecting adaptive hybrids from the same maturity group increased yields by 1186 kg ha-1 for dryland and 2239 kg ha-1 for irrigated compared to unadapted hybrids. The 1992 growing season was cooler than normal and consequently later-maturing hybrids did not fully mature before the first freeze. From a limited irrigation study we found yield and test weight were linearly related: % yield = 0 .3643 (test weight kg m-3) - 177.4, r = 0.97. Hybrids which matured before the first freeze produced up to 7 times more grain and increased test weights by 219 kg m-3 compared to hybrids with immature grain. Greenbug infestation was light in Southeastern Colorado in 1992. Comparing insecticide sprayed plots of greenbug resistant and nonresistant hybrids to unsprayed plots of the same hybrids gave yield reductions from 24 kg ha-1 for resistant hybrids and 1648 kg ha-1 for nonresistant hybrids. |
| 1994 | In our forage sorghum performance tests we added traditional, but still utilized, open-pollinated varieties of coes and cane to track the progress of the newly-bred hybrids. For the last two years, the open-pollinated varieties produced only 26 to 53 % of the test average. Even the least productive hybrid produced 7.8 Mg ha-1 more than the open- pollinated varieties. Because of these results, some forage sorghum growers have replaced their old, open-pollinated varieties with new, higher-yielding hybrids. Growers face a dilemma when conditions force them into planting grain sorghum late. Should they continue with their typical later maturing hybrid, which has high yield potential but may not mature before the first freeze, or should they choose an earlier maturing hybrid with less yield potential but which will mature before the first freeze. This late-planting hybrid choice dilemma was tested by planting June 15 (two weeks after the optimum planting date) using 9 hybrids ranging from early to medium maturity. There was no significant yield difference between hybrids representing early, medium early, and medium maturation (P = 0.10); however, the early and medium early hybrids matured 4 to 16 days before the medium maturity hybrid. Growers would assume less risk from an early freeze by selecting hybrids from early and medium early maturity groups when planting in mid-June. |
| 1995 | Our grain sorghum hybrid performance tests identify climatically and edaphically adapted hybrids. The most adapted hybrids produced as much as 66% higher grain yield under irrigated conditions and 55% under dryland conditions compared to the least adapted hybrids. At a moderate greenbug infestation level, greenbug resistant sorghum hybrids maintained high production levels without insecticide applications. Yield reductions when grown without insecticide treatments were 43 kg/ha for the four most resistant hybrids and 2256 kg/ha for the four least resistant hybrids. An insecticide seed treatment study was conducted for the control of greenbugs on grain sorghum. Gaucho, at 114 g per 45 kg of seed, significantly reduced greenbugs by 74% and produced 6586 kg/ha more grain than the untreated control. In a study to determine profitability of N and P fertilization practices, N and P together produced the highest yields, regardless of placement (broadcast, chisel or seedrow), timing (at planting or inseason), or formulation (dry, liquid or gas). However the yield increase from N and P together did not result in the highest net income. The highest net income was achieved by sidedress N or seedrow P. A study was conducted to evaluate pre-emergence and post emergence herbicides for the control of broadleaf weeds in grain sorghum. Pre-emergence herbicides were more effective than post-emergence treatments for controlling pigweed, Russian thistle and puncture vine. |
| 1996 | Our grain sorghum hybrid performance tests identify climatically and edaphically adapted hybrids. Sorghum producers can increase profit by selecting environmentally adapted hybrids. Over a three year period and at five sites, the most adapted hybrids produced 21% more grain yield than average producing hybrids. Moreover, selecting adapted forage sorghum hybrids produced 40% more yield than average producing hybrids. At a moderately heavy greenbug infestation level, greenbug resistant hybrids maintained high production levels without insecticide applications. The most greenbug resistant hybrid had 1000 times less greenbugs and produced 4539 kg ha-1 more than the least resistant hybrid. An insecticide seed treatment study was conducted for the control of greenbugs on grain sorghum. Gaucho at 177 g per 100 kg of seed, had 20% less leaf loss and produced 1970 kg/ha more grain than the untreated control. Of the 20 treatments in a greenbug insecticide study, Supracide at 0.45 kg/ha had the lowest leaf loss, 18% less than the untreated check. The Supracide treatment also had the highest yield, 1470 kg/ha more than the untreated check. A study was conducted to evaluate post emergence herbicides for the control of pigweed in grain sorghum. The two most costly treatments, Tough with atrazine and Buctril with atrazine all at 0.89 kg/ha, produced the highest yield and the highest net incomes of the nine treatments tested. These two herbicide combinations also caused the least crop injury. |
| 1997 | Our grain sorghum hybrid performance tests identify climatically and edaphically adapted hybrids. The simplest and environmentally friendly way to produce higher grain sorghum yields and profit is by selecting adapted hybrids to fit a particular environment. The most adaptive hybrids produced an average of 59% more grain yield under dryland conditions and 50% more under irrigated conditions than the least adapted hybrids under these same conditions. Similarly, the most adaptive forage sorghum hybrids averaged 57% more forage under dryland and irrigated conditions than the least adaptive hybrids. A study was conducted to evaluate ten commonly used preemergence and post emergence herbicide treatments for the control of stinkgrass and pigweed in dryland grain sorghum. The preemergence application of atrazine had the highest grass control and among the highest pigweed control, while displaying no crop injury. The atrazine treatment resulted in the highest grain yield and highest variable net income of all the herbicides tested. |
| 1998 | The predominate soils for the sorghum producing areas of Colorado are high lime, high alkaline soils. Since the availability of phosphate fertilizers is very low in these soils, soil tests recommend banding of P fertilizers for high yields. We tested six rates, 0, 11, 22, 34, 45 and 56 kg phosphate/ha, of polyammoniated phosphate (10-34-0) fertilizer banded with the seed (seedrow placement) on 0.76 m row spacing in an alkaline silty clay loam soil. We found that the optimum dryland grain sorghum seedrow P rate was about 22 kg phosphate/ha, which was one-half the soil test recommended banded rate. This suggests that seedrow placement of phosphate is an advantageous P banding method as less P fertilizer is needed for high yields. Implementation of our results will lower sorghum growers P fertility expense by one-half, saving them approximately $2.40 to $2.80/ha (assuming 45 kg phosphate/ha is the average recommended P banded rate). Seedrow placement of P fertilizers will also have a positive environmental impact. The adoption of seedrow placement requires that only half as much P fertilizers be applied, which will reduce the amount of P laden soil in the environment . |
| 1999 | Row spacing for dryland grain sorghum varies greatly throughout Southeastern Colorado. The traditional row spacing for dryland continuous sorghum production is either 1.2 m in the northern counties or 1.0 m in the southern counties of Southeastern Colorado; whereas, irrigated sorghum growers use 0.8 m row spacing for grain sorghum production. Moreover, after a wheat crop failure, the traditional wheat-fallow growers sow grain sorghum on the same row spacing as their wheat drill, typically 0.3 m row spacing. To determine the optimum row spacing for dryland grain sorghum production, we tested five row spacings, 0.3 to 1.5 m, at 0 .3 m increments. We found that the highest yield was obtained with the narrowest row spacing, 0.3 m (4080 kg/ha). Along with the higher yields, narrow row spacing also reduced weed pressure by providing early canopy closure which resulted in greater weed suppression. Our findings suggest that each 0.3 m increase in row spacing reduces grain yield by 250 kg/ha. Replacing traditional wide row spacing with narrow row spacing would increase sorghum grain yields by as much as 1000 kg/ha, earning growers an additional $11.50/ha. Since one of the benefits of narrow row spacing is weed suppression, growers adopting narrow row spacing would require less herbicide for weed control. This reduction in herbicide use would increase growers' profit and reduce the amount of pesticide in the environment. |
| 2000 | In Southeastern Colorado, irrigation water is pumped from deep wells. Irrigation costs are much higher in this region than in areas with shallow wells, or from ditch water in river basins. The current low crop commodity markets combined with high energy costs make limited supplemental irrigation more profitable than full irrigation for row crop production in our area. Few reports are available for limited furrow and sprinkler irrigation on grain sorghum and corn. Limited irrigation seeding rate recommendations for grain sorghum and corn currently do not specify irrigation method. We conducted seeding rate studies on limited furrow and sprinkler irrigation for both grain sorghum and corn (25,100 to 55,900 seeds/ha for grain sorghum; 8,100 to 14,200 seeds/ha for corn) to determine the optimum seeding rate for these crops. We define limited irrigation as applying 1520 to 2030 cubic meter/ha of water during the growing season. We found the seeding rates that produced maximum yield differed between limited furrow and limited sprinkler irrigation methods. The highest grain sorghum and corn yields for limited furrow irrigation occurred with the lowest seeding rates tested (25,100 and 8,100 seeds/ha, respectively); whereas, the seeding rates that produced highest yields for limited sprinkler irrigation were moderately high (grain sorghum, 44,600 seeds/ha; corn, 10 ,500 seeds/ha). The optimum seeding rate for these limited irrigation systems indicates that limited furrow irrigation is more aligned with dryland seeding rates, and limited sprinkler irrigation is closer to fully irrigated seeding rates. Therefore, we recommend separate seeding rates for limited irrigation grain sorghum and corn depending on irrigation method, a lower seeding rate for furrow irrigation, approximately, 25,000 seeds/ha for grain sorghum and 8,000 seeds/ha for corn, and a higher seeding rate for sprinkler irrigation, approximately, 45 ,500 seeds/ha for grain sorghum and 10,500 seeds/ha for corn. |
| 2001 | Soil test recommendations for Southeastern Colorado typically recommend banding zinc at 2.24 kg per ha to both dryland corn and grain sorghum. In our area, classic zinc deficiency symptoms are often encountered in corn without zinc fertilization. The addition of zinc to these corn fields causes the symptoms to disappear. Grain sorghum in our area displays no visible zinc deficiency symptoms, but growers report yield increases with zinc to their grain sorghum crops. To study zinc fertilization on dryland corn and grain sorghum, we applied zinc chelate at 0, 0.224, 0.448, 0.672, 0.896, and 1.12 kg per ha with the corn and grain sorghum seed at planting (seedrow applied) in a sandy loam soil. The soil test reported 0.1 ppm Zn level in our 0 to 0.2 m depth sample. The soil test recommendation for our 3760 kg per ha yield goal for corn and grain sorghum was 2.24 kg per ha of banded zinc. Corn yields increased with seedrow zinc up to 0.336 kg per ha (one-sixth the recommended rate). The 0.336 kg per ha Zn rate produced 627 kg per ha more grain than the treatment without applied zinc. Grain sorghum did not respond to applied zinc. Grain sorghum yields fluctuated no more than 120 kg per ha from the mean with zinc fertilization. This is the third year we have tested both corn and grain sorghum in this zinc rate study. All three years corn responded to seedrow zinc with optimum zinc rates ranging from 0.336 to 0.672 kg per ha. In five out of the last six years, grain sorghum yields did not increase with applied zinc. The one year we reported a response from zinc fertilizer on grain sorghum yields was an exceptionally high rainfall year. Because of these results, in our area, we recommend seedrow applied zinc at 0.336 to 0.672 kg per ha for dryland corn production. We do not recommend zinc fertilization for dryland grain sorghum production, since grain sorghum seldom responded to applied zinc. For a zinc cost of less than $0.80 per ha, dryland corn growers could realize about $8.00 per ha net income gain from a low rate of seedrow zinc. Moreover, dryland grain sorghum producers could save about $0.80 per ha by not fertilizing with zinc. Any increase in grower profit produces a more stable agricultural base. The viability of rural communities that rely on agriculture is secured by profitable agriculture. Implementing our recommendations would result in a positive environmental impact. Using low-rate seedrow applications of zinc to dryland corn and eliminating zinc fertilizers from dryland grain sorghum would reduce the amount of zinc, and its potential heavy metal contaminates, in the environment. |
| 2002 | Most seeding rate recommendations for limited irrigation grain sorghum are between dryland and fully irrigated rates: 22,300 to 40,500 seeds per ha. Currently there is no grain sorghum seeding rate recommendation distinction between limited furrow irrigation and limited sprinkler irrigation. For this study, limited furrow irrigation was defined as receiving a pre-irrigation (if winter moisture was lacking) and one in-season irrigation at heading, and limited sprinkler irrigation was defined as a similar amount of water used for furrow irrigation but applied with a sprinkler. Typically, the amount of irrigation applied ranged from 0.152 ha-m per ha (if only the in-season irrigation was needed) to 0.304 ha-m per ha (if both the pre-irrigation and the in-season irrigation were needed). We tested four seeding rates under limited furrow and sprinkler irrigation: 12.4, 20.3, 27.5, and 31.6 X 1000 seeds per ha. This resulted in 10.7, 14.8, 18.6, and 20.4 X 1000 plants per ha. The furrow site received one in-season irrigation of 0.175 ha-m per ha of water. The sprinkler site received 0 .127 ha-m per ha of water. In this study, the highest yielding seeding rate for limited furrow irrigation was the lowest seeding rate tested, 12,400 seeds per ha (10,700 plants per ha). Conversely, the highest yielding seeding rate for limited sprinkler irrigation was the highest seeding rate tested, 31,600 seeds per ha (20,400 plants per ha). Under limited sprinkler irrigation yields increased linearly with increasing seeding rates, whereas, with limited furrow irrigation yields decreased linearly with increasing seeding rates. We conducted this limited irrigation seeding rate study for two years and this divergent linear response was similar for both years. Therefore, we recommend that limited irrigation grain sorghum seeding rates be based on irrigation method: for furrow, a low seeding rate similar to a dryland rate, 12,200 to 24,300 seeds per ha (10,500 plants per ha minimum), and a high seeding rate similar to a fully irrigated rate, 28,400 to 46,600 seeds per ha (19,400 plants per ha minimum), for limited sprinkler irrigation. If sorghum growers are using improper limited irrigation seeding rates in the range we studied, then by adhering to our seeding rate recommendations they could increase their grain sorghum yields from 320 to 1320 kg per ha, or $3.80 to $16.10 per ha (using the loan rate as the expected price). Increasing grower profitability adds to economic stability in rural communities where agriculture is the economic base. |
| 2003 | The majority of grain sorghum produced in Southeastern Colorado is grown using conventional tillage in a continuous grain sorghum rotation. There are problems with conventional tillage: it leaves little soil-protecting residue and it causes soil water loss. No-till solves conventional-till's shortcomings by leaving residue that conserves both soil and water. However, long-term, continuous no-till grain sorghum is unprofitable because yield and income gradually decrease because of increased competion from grassy weeds. Ridge-till has some of the moisture saving benefits of no-till, and grassy weeds are controlled with cultivation. Moisture conservation with ridge-till gives it yield and income advantages in dry years compared to conventional-till. In the five crop years of this study (no crops were grown in 2002 because of drought), we compared yield and economics of ridge-till, no-till and conventional-till for dryland continuous grain sorghum production. There was no yield difference between no-till and ridge-till, until last year, when ridge-till yielded more than no-till. For two out of five years, no-till produced more than conventional-till, and for three out of five years, ridge-till produced more than conventional-till. The overall linear trends of yield and income for no-till and conventional-till significantly decreased with time compared to ridge-till. The first two years of this study were much wetter than average, and the last three crop years of this study had average to above average annual precipitation. Ridge-till yields were higher than conventional-till yields in the drier years of this study. Variable net income levels of conventional-till compared to ridge-till have likewise declined. There was an obvious increase in grassy weeds in the no-till system compared to the ridge-till system. The increase in sandbur, shattercane, and volunteer in the no-till system have steadily decreased yields and income compared to ridge-till. The longer the systems were held in dryland continuous grain sorghum, the greater the advantages of ridge-till were compared to no-till and conventional-till (especially in drier years). It took a few years of no-till continuous grain sorghum before grassy weeds proliferated and reduced yields and incomes compared to ridge-till. In drier years, the moisture savings from herbicide weed control compared to tillage weed control helped ridge-till produce higher yields than conventional-till. Yields and income of continuous grain sorghum can be maintained in the long-term if ridge-till practices are adopted. After five cropping years, ridge-till produced 188 to 314 kg/ha more than no-till and conventional-till, which translated into at least $0 .77/ha more net income for ridge-till. Along with higher yield and income, converting to ridge-till also conserves soil compared to conventional-till. |
| 2004 | The importance of limited irrigation (supplemental irrigation) has traditionally been associated with very low capacity irrigation wells. The current high fuel prices and associated pumping costs places new emphasis on limited irrigation as a replacement for full irrigation. We define limited irrigation on corn and grain sorghum as applying one in-season furrow irrigation of less than 10.28 ha cm or a similar amount of water applied with a sprinkler. Applying less than 10.28 ha cm as an in-season irrigation assumes that the soil water profile is full from sufficient winter moisture, or, if winter moisture is lacking, the soil water profile is filled by pre-irrigation. Limited irrigation becomes a more profitable choice as fuel costs increase. Our research suggests that the decision point for conversion from full irrigation to limited irrigation with our current costs, and the loan rate ($0 .056/L) as the expected grain price, is $3.94/ha cm pumping cost for corn and $4.46/ha cm pumping cost for grain sorghum. With a commodity price of $0.065/L for corn and grain sorghum, the decision point for conversion from full to limited irrigation increases to $4.87/ha cm pumping cost for both corn and grain sorghum. An economic comparison between corn and grain sorghum under full and limited irrigation is dependent on commodity price. The current loan rate for corn and grain sorghum is equal ($0.056/L). Using the same commodity price for corn and grain sorghum provides grain sorghum with higher net income than corn under both limited and full irrigation. However, when corn and grain sorghum commodity prices are above the loan rate, corn frequently has a $0.009/L price advantage compared to grain sorghum in the local market. Corn priced $0.009/L higher than grain sorghum provides corn with higher net income than grain sorghum under both full and limited irrigation. Decreases in commodity prices give limited irrigation the income advantage over full irrigation. If the current loan rate becomes the price growers receive for their corn and grain sorghum crops next season and irrigation costs remain high, limited irrigation will continue to be more profitable than full irrigation for smaller capacity wells. The current high cost of fuel makes pumping cost the most responsive variable driving conversion from full to limited irrigation. Nonetheless, inputs such as fertilizer and seed, which differ between full and limited irrigation regimes, favor limited irrigation when these input costs increase. Limited irrigation conserves water. Limited irrigation lengthens the irrigation well life by as much as 2.5 times compared to full irrigation pumping. Increasing irrigation well life assures dependable and stable farm income over the long-term. |
| 2005 | Strip-till is a tillage system being adopted by many row crop producers in Colorado. It is a modified no-till system with one tillage operation used for fertilizer placement. The crop is planted into the same rows where tillage occurred and the fertilizer was placed. In this study we compared strip-till placement of anhydrous N to surface applied liquid N for both sprinkler irrigated grain sorghum and corn production. For grain sorghum, strip-till and surface applied N produced the same yield, 132 kg/ha. For corn, surface applied N produced 17 kg/ha more than strip-till N. There were no significant plant density differences between strip-till N and surface applied N for corn and grain sorghum. The advantages of strip-till compared to no-till are the use of anhydrous N fertilizer (the least expensive form of N fertilizer), deeper and more readily available placement of immobile nutrients, potential compaction alleviation, and early planting from enhanced soil warming. The disadvantages of strip-till compared to no-till are the horsepower and fuel use requirements for injecting fertilizers with knives or subsoiler shanks and the potential of drying the soil where planting occurs. We believe that one of the disadvantages of strip-till, drying of the soil, caused the corn yield reduction in strip-till N application compared to surface applied N. The short temporal space between the strip-till application and the corn planting date (three weeks) did not allow sufficient time for moisture to occur. However, this moisture loss was not reflected in plant stand: there was no plant density difference in corn between strip-till N and surface applied N. We expected that corn and grain sorghum yields would be unaffected by N placement since N is a mobile nutrient. Therefore, it was not surprising that grain sorghum yields were identical for both strip-till N and surface applied N. There appears to be no yield advantage from strip-till placement of N compared to surface applied N . In fact, strip-till N placement may be a detriment if planting is performed too soon after strip-tilling. The benefit of strip-till may be placement of immobile nutrients such as P. More research in strip-till placement of immobile nutrients needs to be conducted. Conversion from conventional tillage to strip-till would conserve energy and soil (multiple tillage operations with conventional tillage are reduced to only one tillage operation with strip-till). For sorghum, even without a yield increase, there was a $6/ha economic advantage for strip-till compared to no-till, when comparing application and N costs, primarily because anhydrous is $0.07/kg less than liquid N. |
| 2006 | Skip row planting is an old idea that is being revitalized for dryland row crop production in the drier areas of the High Plains. The two main advantages of skip row planting compared to solid planting are reported to be late-season water availability from water stored in the skip row and less input costs because fewer rows are planted. Our results from this very dry year of planting grain sorghum in 0.76 m rows show that the skip row treatments produced more grain yield than planting all rows. The skip row/plant two rows treatment produced 188 kg/ha more than planting all rows, and the skip row/plant row treatment produced 125 kg/ha more than planting all rows. The moisture conserved with skip row may have contributed to higher grain sorghum yields. Seeding density was decreased with skip row compared to planting all rows, 8,870 seeds/ha for skip row/plant two rows and 7,088 seeds/ha for skip row/plant row compared to 14,175 seeds/ha for all rows planted. Some of the yield increase with skip row may be attributed to adjusting population density to moisture conditions. Seeding density manipulation may be as important as skip row patterns for sustaining yields during dry weather. In upcoming studies, we will investigate the late-season water conservation strategy of lowering the seeding densities of solid planting to the seeding densities obtained with skip row. Skip row planting is not a new idea. For many years, cotton growers in Texas have used skip row to take advantage of government programs. The skip row area was considered set aside acres and only the cotton in the planted rows was counted as production acres. This has caused a potential insurance problem with skip row plantings for other row crops because only 0.51 m on each side of the planted row is considered planted area. Currently, only the crop area that is considered planted is insurable; therefore, insurance coverage is dependent on growers' skip row planting patterns. With an alternate skip row pattern on 1.01 m rows, only 50% of the field is considered planted and insurable. Based on our modest skip row grain sorghum yield (125 kg/ha to 188 kg/ha) and income ($2.59/ha to $3.89/ha at $0.026/kg) as well as crop insurance uncertainties, we believe that few growers would consider converting to skip row planting. However, for those growers considering skip row planting, we recommend that they consult with their local FSA office before planting to find the latest information on the skip row planting insurance issue. |
| Impact | |
| 1999 | Improving sorghum production with neutral cost evaluations that increase yield, such as hybrid performance tests, or by lowering inputs, such as fertilizers and pesticides, increase growers' profit and reduce environmental impacts. Since growers are the economic and environmental engine of rural communities, having profitable, environmentally sound growers keeps Southeastern Colorado economically and environmentally healthy. |
| 2000 | Selecting the proper seeding rate for limited irrigation based on irrigation method would increase grain sorghum and corn yields 314 to 753 kg/ha, bolstering grower profit $4.50 to $7 .30/ha. Adjusting limited irrigation seeding rates to the irrigation method would have a neutral environmental effect. However, a change from full irrigation to limited irrigation would conserve water, fuel, and fertilizers: potentially, half as much fuel would be used for pumping, half as much underground water would be depleted, and one-quarter less fertilizers would be applied. |
| 2001 | Reducing zinc rates, while maintaining high production levels of dryland corn and grain sorghum, will make growers more profitable. Grower profitability is the key to economic stability in rural communities that rely predominately on agriculture. |
| 2002 | Grain sorghum growers following our recommendations for limited irrigation seeding rates will be more profitable. Grower profitability is the key to rural economic viability, especially those rural communities primarily reliant on agriculture as their foundations. |
| 2003 | The conservation of soil and soil water attained by converting from conventional tillage to ridge-till for dryland continuous grain sorghum production provides a more stable environment, higher yields and higher incomes for grain sorghum producers. |
| 2004 | With the current high pumping costs and low commodity prices, limited irrigation provides higher income for corn and grain sorghum producers than full irrigation. The water conservation savings by adopting limited irrigation will lengthen irrigation well life by more than two fold. Increasing irrigation well life assures dependable and stable farm income over the long-term. |
| 2005 | Replacing conventional tillage with strip-till would conserve fossil fuel and soil. With conventional tillage the soil is tilled multiple times before planting, strip-till reduces the tillage operations to one, a fertilizer placement operation. Even without a yield advantage, strip-till is more profitable than no-till because anhydrous, the less cost N fertilizer, can be injected into the soil with strip-till; whereas, no-till is reliant on liquid N, a more costly form of N. Greater grower success and income may be achieved when converting to strip-till by increasing the time between strip-till and planting operations. Growers adopting strip-till technology should perform their strip-till operation in the fall and winter to avoid yield losses from planting too soon after strip-tilling. |
| 2006 | Based on our slight yield and income increases for this very dry year as well as insurance uncertainties with skip row compared to solid planted grain sorghum, we believe that few growers would consider converting to skip row planting. Furthermore, planting all rows and lowering plant population densities to adjust for dry conditions may potentially achieve a similar water conservation advantage of late-season water availability obtained with skip row. Moreover, there would be no crop insurance planting issues with low population, all rows planted grain sorghum since this method of planting is already insurable. |
| Publications | |
| 1993 |
LARSON, K. J., SCHWEISSING, F. C. AND THOMPSON, D. L. 1993. Sorghum Hybrid Performance Tests inColorado. 1992. Tech. Rept. TR93-1. Colo. State Univ. Ag. Exp. Stn., Dept. of Agronomy, 48 p . |
| 1994 |
LARSON, K.J., SCHWEISSING, F. C. AND THOMPSON, D. L. 1994. Sorghum Hybrid Performance Tests in Colorado, 1993. Technical Report TR94-3. Colorado State University Agricultural Experiment Station, Fort Collins, CO |
| 1995 |
LARSON, K. J., SCHWEISSING, F. C. AND THOMPSON, D. L. 1995. Sorghum Hybrid Performance Tests in Colorado, 1994. Colo. State Univ. Agric. Exp. Sta. Tech. Rep. TR95-2 |
| 1996 |
LARSON, K.J., SCHWEISSING, F.C., and THOMPSON, D.L. 1996. Sorghum Hybrid Performance Tests in Colorado, 1995. Technical Report TR96-1. CSU, AES, Department of Soil and Crop Sciences, 54 p |
| 1997 |
LARSON, K. J., SCHWEISSING, F. C., AND THOMPSON, D. L. 1997. Sorghum hybrid performance tests in Colorado, 1996. Technical Report TR97-4. CSU, AES, Department of Soil and Crop Sciences, 40 p |
| 2001 |
Larson, K.J., Schweissing, F.C., and Thompson, D.L. 2001. Sorghum hybrid performance tests in Colorado, 2000. Colorado Agricultural Experiment Station Technical Report Series, TR01-2. Colorado State University, Fort Collins, CO. 53p. |
| 2002 |
Larson, K.J., Schweissing, F.C., and Thompson, D.L. 2002. Sorghum hybrid performance tests in Colorado, 2001. Colorado Agricultural Experiment Station Technical Report, TR02-2. Colorado State University, Fort Collins, CO. 52p. |
| 2003 |
Larson, K.J., et al. 1999. Plainsman Research Center, 1998 research results. Ag. Exp., Station , Coop. Ext., Colorado, State Univ., Ft. Collins, 125p. "unpub" Larson, K.J., et al. 2000. Plainsman Research Center, 1999 research results. Ag. Exp. Station, Coop. Ext., Colorado State Univ., Ft. Collins, 127p. "unpub" Larson, K.J., et al. 2001. Plainsman Research Center, 2000 research results. Ag. Exp. Station, Coop. Ext., Colorado State Univ., Ft. Collins, 136p. "unpub" Larson, K.J., et al. 2002. Plainsman Research Center, 2001 research results. Ag. Exp. Station, Coop. Ext., Colorado State Univ., Ft. Collins, 113p. "unpub" |
| 2004 |
Larson, K., D. Thompson, and D. Harn. 2001. Limited and full irrigation comparison for corn and grain sorghum. AES, Dept. of Soil and Crop Sci., Plainsman Research Center, Colo. State Univ., Ft. Collins, CO. 10p. Published at Colo. State Univ. web site: http://www.colostate .edu/depts/prc/pubs/LimitedandFullIrrigationComparisonforCorn.pdf |
| 2005 |
Larson, K.J., Berrada, A., and Thompson, D.L. 2005. Sorghum hybrid performance trials in Colorado, 2004. Technical Report TR05-03. Ag. Exp. Station, Fort Collins, CO. 49p. |
| 2006 |
Larson, K.J., Berrada, A., and Thompson, D.L. 2006. Sorghum hybrid performance trials in Colorado, 2005. Technical Report TR06-04. AES, CSU, Fort Collins, 45p. |