Full-season Soybean Research Articles

Enhanced seed yield of full-season soybean when rotated with cereals and cover crops as compared to monoculture in a long-term experiment

Enhanced seed yield of full-season soybean when rotated with cereals and cover crops as compared to monoculture in a long-term experiment

Soybean seed yield and protein response to crop rotation and fertilization strategies in previous seasons

Soybean seed yield and protein response to crop rotation and fertilization strategies in previous seasons

Defining soybean maturity group options for contrasting weather scenarios in the American Southern Cone

Soybean genotypes are grouped in maturity groups (MG) based on the response to photoperiod, and a genotype belonging to a particular MG is recommended according to latitude and planting date. From an agronomic viewpoint, an “optimum maturity group” (MG opt ) can be defined as the one that maximizes soybean yield in a particular environment, and not necessarily corresponds with the recommended MG based on thermo-photoperiod response. Our objectives were to (i) delineate spatial pattern of MG opt across contrasting environmental conditions for full-season soybean using geostatistics, and (ii) test whether the weather scenario change the spatial distribution of the MG opt . We hypothesized that, for the same region, the MG opt in dry years (i.e. La Niña phase) is larger than in humid years (i.e. El Niño phase). We analyzed multi-environment trials of full-season soybean (1675 site-years) using recent soybean genotypes and management practices across the Southern Cone of America. The MG opt ranged between 3.8 and 7.8 across regions and ENSO phases. The geostatistics approach indicated a spatial MG opt auto-correlation. The map for each ENSO phase indicates zones with contrasting MG opt and independently of ENSO phase, MG opt increased as latitude decreased. Also, for a particular latitude range, MG opt also varied according to longitude, suggesting that its variation can be associated with rainfall pattern and soil types in the region. Our approach delineated the distribution of MG opt for the American Southern Cone and highlighted that the inclusion of ENSO phase is important for guiding farmers MG options at regional scale. • Optimum maturity groups ranged from 3.8 to 7.8 in the Southern Cone of America. • Previous optimum maturity groups definition was improved using spatial analysis. • For a particular latitude, optimum maturity groups also varied according to longitude. • Optimum maturity groups varied with weather scenario in some areas of the Southern Cone.

Integrated Weed Management Systems to Control Common Ragweed (Ambrosia artemisiifolia L.) in Soybean

As resistance to herbicides limits growers' weed management options, integrated weed management (IWM) systems that combine non-chemical tactics with herbicides are becoming critical. A 2 year integrated weed management (IWM) study was conducted at three locations in VA, USA. The factorial study evaluated: (1) soybean planting date (early or late planted) (2) with or without winter cover (cereal rye/wheat or no cover), and (3) with or without harvest weed seed control (HWSC). Prior to soybean planting in the first year, winter cover resulted in a 22% reduction in common ragweed density compared to no cover. At soybean harvest in the first year, the lowest common ragweed densities were in the late planted plots following winter wheat, and common ragweed aboveground biomass was reduced by 46 and 22% at two locations in late planted compared to early planted soybean. To evaluate the impact of the first year's treatments and HWSC, full season soybeans were planted across the trial in the second year. Prior to soybean planting in the second year, late planting in the first year common ragweed density was reduced by 83% at one location, but significant reductions were not observed elsewhere. When comparing winter cover to no cover, common ragweed densities were reduced by 31 and 49% at two locations and densities were similar at the third location. Harvest weed seed control reduced common ragweed density by 43% at one location compared to the conventional harvest plots but no significant reductions were observed at the other locations or at other rating timings. However, there was a significant location by planting date by winter cover interaction and the overall lowest common ragweed densities (4.1 to 10.3 plants m−2) were in the late planted plots with winter cover. This research indicated that winter cover, late planting, and HWSC can reduce common ragweed populations with late planting being the most influential. Therefore, double-cropping soybean after wheat is likely the most viable means to better control common ragweed using IWM as it combines both winter cover and late planting date.

Modeling economic-environmental decision making for agricultural land use in Argentinean Pampas

Abstract This research evaluates the economic and environmental impacts of land allocation to crops and extensive livestock production in the Argentine Pampas using compromise programming. Two economic indicators (gross margin, direct costs) and five environmental indicators (organic carbon input to soil, nutrient balances, agrochemicals impact and soil erosion) are considered. The tradeoff between economic and environmental objectives is assessed and the preferred land allocation schemes determined by the multicriteria model are compared to the current land use in the region of Pergamino, North of Buenos Aires, Argentina. Results indicate that it is important to consider not only the environmental-economic tradeoff in farming, but also the conflict across different environmental criteria in order to determine whether it is reasonable to stimulate activities which improve some environmental indicators at the expense of getting less desirable values in others. For instance, an increase of productivity in agriculture enhances soil organic carbon content but it may increase the risk of contamination with agrochemicals and nutrients. Results are consistent with the notion that extensive crop-livestock production systems are more balanced than continuous crop farming. According to model results, optimal land assignment is a combination of crop and livestock activities (62 and 38% of land, respectively) which is associated with lower agrochemical use, greater organic carbon input to soil, better soil protection from erosion and more efficient nutrient cycling. This land assignment presents a decrease of 20% in the economic gross margin compared to the continuous agriculture scheme that maximizes the economic result. The comparison between current land use and the optimal land assignment based on model results show that farmers assign a smaller fraction of land to extensive livestock production (2–4%), than in the most balanced compromise solution (38%). Results also suggest that it would be appropriate to encourage farmers to reduce the area of land assigned to full-season soybeans.

Dual Cropping Winter Camelina with Soybean in the Northern Corn Belt

Sustainably balancing biofuel crop production with food, feed, and fiber on agricultural lands will require developing new cropping strategies. Double‐ and/or relay‐cropping winter camelina (Camelina sativaL.) with soybean [Glycine max(L.) Merr.] may be a means to produce an energy and food crop on the same land in a single year. A study was conducted between 2009 and 2011 in west central Minnesota to evaluate yields, seed quality, economics, and within‐field energy balance of winter camelina–soybean double‐ and relay‐cropping systems compared with a conventional monocropped full‐season soybean. Systems included methods to hasten camelina harvest (e.g., swathing and desiccating) to promote early soybean growth. Camelina seed yields were unaffected by cropping system and ranged from 1.1 to 1.3 Mg ha−1. Relay‐cropped soybean yields were greater than double‐cropped soybean and were 58 to 83% of that for the monocropped control. Seed oil and protein content of double‐ and relay‐cropped soybean were comparable to their monocropped counterpart and combined seed oil yield for the dual crop systems was as much as 50% greater. Net economic returns for the relay‐crop treatments were competitive with that of the full‐season soybean. Moreover, net energy of the relay‐crop treatments was generally as high as the sole soybean crop, but energy efficiency (outputs/inputs) was less due to greater inputs. Results indicate that dual cropping of winter camelina with soybean is agronomically viable for the upper Midwest and might be an attractive system to growers seeking a “cash” cover crop.

Influence of Deep Tillage, a Rye Cover Crop, and Various Soybean Production Systems on Palmer Amaranth Emergence in Soybean

Glyphosate-resistant Palmer amaranth has become a major threat to soybean production in the southern United States. Arkansas soybean producers rely heavily on glyphosate-resistant soybean; hence, an alternative solution for controlling resistant Palmer amaranth is needed. A field experiment was conducted at Marianna, AR, during 2009 and 2010 in which soybean production systems were tested in combination with deep tillage and no tillage to determine the impact on Palmer amaranth emergence. To establish a baseline population, 250,000 glyphosate-resistant Palmer amaranth seeds were placed in a 1-m2area in the middle of each plot and incorporated in the soil, and emergence was evaluated five times during the season. Production systems of full-season soybean with a rye cover crop or soybean double-cropped with wheat, which had high amounts of plant residue on the soil surface reduced Palmer amaranth emergence more than systems without deep tillage and a cover crop or wheat. When used in combination with deep tillage, these systems reduced Palmer amaranth emergence by 98 and 97%, respectively, in 2009 and by 73 and 82%, respectively, in 2010. Deep tillage alone caused an 81% reduction in emergence averaged over both years. Soybean double-cropped with wheat used in combination with deep tillage provided a 95% reduction in Palmer amaranth emergence over the 2-yr period. This research shows that deep tillage in combination with soybean production systems that have high amounts of residue on the soil surface are alternative means for providing a high level of control of glyphosate-resistant Palmer amaranth and could lessen the dependence on chemical weed control.

Short- and full-season soybean in stale seedbeds versus rolled-crimped winter rye mulch

AbstractStale seedbeds are used by organic growers to reduce weed populations prior to crop planting. Rye mulches, derived from mechanically killed (rolled and crimped) winter rye cover crops, can serve the same purpose for spring-planted organic crops. Both methods can also be employed by conventional growers who face looming problems with herbicide resistant weeds. The objective of this research was to compare these methods over 2 years in central Minnesota in terms of weed seedling emergence, populations, biomass and manual-weeding times, as well as stands and yields of short-season and full-season soybean varieties planted late, in mid June. Rye mulch greatly lowered both pre- and post-planting weed populations of common annual weeds, which substantially affected necessity for augmented weed control. For instance, the need for within-crop manual-weeding was low for soybean planted into rye mulch (0–6 h ha−1), but ranged from 15 to 66 h ha−1of labor for soybean planted in stale seedbeds and augmented by inter-row cultivation. However, rye mulch lowered soybean yield potential by 800–1000 kg ha−1compared with stale seedbeds in 1 of 2 years. With organic feed-grade soybean seed valued at $1 kg−1, conventional soybean seed at $0.5 kg−1, and labor for manual-weeding at $10 h−1, the use of rye mulch compared with stale seedbeds augmented by manual-weeding are equally rational choices for organic growers in central Minnesota (assuming labor is available for hand-weeding), but rye mulches probably would be a wise financial option for conventional growers compared with hand-weeding. Lastly, full-season soybean had higher yields than short-season soybean and probably represents a prudent selection in central Minnesota, regardless of the late planting date requirements for both the rye mulch and stale seedbed systems.

Distribution of the Long-Horned Beetle,Dectes texanus,in Soybeans of Missouri, Western Tennessee, Mississippi, and Arkansas

The long-horned beetle, Dectes texanus LeConte (Coleoptera: Cerambycidae), is a stem-boring pest of soybeans, Glycine max (L.) Merrill (Fabales: Fabaceae). Soybean stems and stubble were collected from 131 counties in Arkansas, Mississippi, Missouri, and Tennessee and dissected to determine D. texanus infestation rates. All states sampled had D. texanus present in soybeans. Data from Tennessee and Arkansas showed sample infestations of D. texanus averaging nearly 40%. Samples from Missouri revealed higher infestation in the twelve southeastern counties compared to the rest of the state. Data from Mississippi suggested that D. texanus is not as problematic there as in Arkansas, Missouri, and Tennessee. Infestation rates from individual fields varied greatly (0–100%) within states. In Tennessee, second crop soybeans (i.e. soybeans planted following winter wheat) had lower infestations than full season soybeans. A map of pest distribution is presented that documents the extent of the problem, provides a baseline from which changes can be measured, contributes data for emergency registration of pesticides for specific geographic regions, and provides useful information for extension personnel, crop scouts, and growers.

SDI Dripline Spacing Effect on Corn and Soybean Yield in a Piedmont Clay Soil

A subsurface drip irrigation (SDI) system was installed in the Piedmont of North Carolina in a clay soil in the fall of 2001 to test the effect of dripline spacing on corn and soybean yield. The system was zoned into three sections; each section was cropped to either corn (Zea mays L.), full-season soybean [Glycine max (L.) Merr.], or winter wheat (Triticum aestivum) double cropped to soybean representing any year of a typical crop rotation in the region. Each section had four plots; two SDI plots with dripline spacing at either 1.52 or 2.28 m, an overhead sprinkler irrigated plot, and an unirrigated plot. There was no difference in average corn grain yield for 2002–2005 between dripline spacings or between either dripline spacing and sprinkler. Irrigation water use efficiency (IWUE) was greater for sprinkler irrigated corn than for either SDI treatment and there was no difference in IWUE in soybean. Water typically moved laterally from the driplines 0.38 to 0.50 m. SDI yield and IWUE increased relative t...

Long-term Crop Rotation and Tillage Affects Wheat and Double-crop Soybean and Selected Soil Properties

Field studies were conducted from 1996 through 2006 in southeastern Kansas to evaluate the influence of previous crop [corn, Zea maysL.; grain sorghum, Sorghum bicolor(L.); and soybean, Glycine max(L.) Merr.] and tillage system (conventional versus no-till) on grain yield of hard red winter wheat (Triticum aestivumL.) and double-crop soybean in a 2-year rotation. On average, wheat yield was greater following corn or soybean than following grain sorghum. Yield of double-crop soybean averaged 20% greater when wheat followed corn or grain sorghum than when wheat followed full-season soybean. Tillage system influenced grain yield of double-crop soybean more than it influenced wheat yield. Double-crop soybean yield often was greater for continuous no-till than for conventional or one-time no-till per cropping cycle. Soil analyses at the end of the study showed that total C and total N were greater for no-till than for conventional in the 0- to 3-inch depth, but total C and total N were greater for conventional than no-till in the 3- to 6-inch depth. In the multi-cropping systems of the eastern Great Plains, both crop rotation and tillage system can significantly influence grain yield and selected soil properties.

Seed Coat Technology Affects Yields of Relay Intercrop, Full Season, and Double Crop Soybean in Upstate Missouri

Seed Coat Technology Affects Yields of Relay Intercrop, Full Season, and Double Crop Soybean in Upstate Missouri

US effort in the development of new crops (Lesquerella, Pennycress Coriander and Cuphea)

The US effort for the development of new crops is directed toward the advancement of crops that can be grown in rotation with traditional commodity crops, off-season production and utilization of acreage not currently under cultivation. This effort is intended to have no or minimal impact on crop rotations that are sources for food production. The high oil content and the fatty acid profiles of mustard crops make them suitable for utilization as both fuels and base stocks for functionalized industrial chemicals. Pennycress (thlaspi arvense) and lesquerella (lesquerella fendleri) are representatives of this family and have received much attention due to their potential to grow over winter in rotation with soybean production throughout the Midwest (pennycress) or as a winter annual in the desert southwest (lesquerella). Pennycress is an oilseed crop that produces 36% oil with a wide distribution of fatty acids (principal fatty acid is erucic acid 37%) that make it suitable for production of biodiesel. The key aspect of pennycress is that its lifecycle is complete such that a full season soybean can follow its production in the same growing season. Lesquerella is an oilseed crop containing 30% oil that is composed of 60% hydroxy fatty acids. Hydroxy fatty acids are used in a wide range of industrial and cosmetic applications. Two other New Crops currently under investigation are cuphea and coriander. Cuphea is an oilseed crop that contains 35% oil that is composed of medium chain saturated fatty acids. The current cuphea variety under investigation is high in capric fatty acid (76%) with other cuphea species producing high levels of lauric acid. Cuphea can be grown throughout the Midwest but suffers from several agronomic traits that are currently limiting is potential adaptation. Coriander is also an oilseed crop with 25% oil where the main fatty acid is petroselinic acid (76%). Coriander can be grown under a short season production and has potential to rotate as a second crop following winter wheat. Petroselinic acid can be ozonolytically cleaved into adipic and lauric acids both high volume industrial chemicals.

Early-season Soybean as a Trap Crop for Stink Bugs (Heteroptera: Pentatomidae) in Arkansas’ Changing System of Soybean Production

Early-season soybean, Glycine max L. Merrill, was evaluated in Arkansas soybean fields as a trap crop for a complex of stink bug species that included Nezara viridula L., Acrosternum hilare (Say), and Euschistus servus (Say). Early-season soybean production systems (ESPSs) are composed of indeterminate soybean cultivars planted in April. In the first year of a 2-yr study, field-scale trap crops ( approximately 0.5-1.0 ha) of maturity group (MG) III and IV soybean were planted adjacent to production fields of MG V soybean. Stink bugs were attracted first to the ESPS trap crops and were twice treated with insecticide, yet damaging populations developed later in the MG V soybean adjacent to the trap crops. General sampling and observations of low stink bug densities in commercial fields of soybean and corn across the study area suggested that stink bugs were widely distributed across the agricultural landscape. These observations and the subsequent discovery of additional ESPS fields outside the study area suggested that developing populations in the adjacent MG V soybean probably did not originate from the trap crops. However the source of the populations colonizing MG V soybean could not be determined, and we concluded that the scale of future experiments should be increased to better control stink bugs dispersing from other ESPSs outside the study area. In the second year of the study, the experiment was expanded in size to a farm- or community-scale project where entire fields of ESPSs (8-32 ha) were used as trap crops. Insecticide was applied to the trap-crop fields and other fields of ESPSs within a 0.8-km radius of targeted response fields, yet again there was no apparent effect on subsequent populations of stink bugs in the MG V response fields. With the recent expansion of ESPSs in Arkansas, it may be difficult to use ESPSs as a trap crop to lower stink bug populations across large enough areas to suppress populations in late-season soybean. Also, multiple soybean cultivars are generally planted across a 2- or 3-mo period in Arkansas, which results in staggered soybean development across the landscape and extends the time period that soybean is attractive to colonizing stink bugs. Trap crops of ESPSs are only attractive for oviposition for up to 4-5 wk and cannot protect full-season soybean production systems (FSSPSs) for such an extended time period. This shift in production systems may limit the use of ESPS trap crops for management of stink bugs unless highly coordinated efforts are made to synchronize soybean maturity and control stink bugs in ESPSs across large geographic areas.

Wheel Traffic to Narrow-Row Reproductive-Stage Soybean Lowers Yield

Soybean producers need to know the loss associated with sprayer tire damage to fully determine the cost and benefit of reproductive-stage pest management strategies. Experiments were conducted to determine the yield loss resulting from wheel traffic applied at the R4-stage to full-season and double-crop soybean planted in three row spacings. Wheel traffic reduced yield when planted in 7.5- and 15-inch row spacing. Traffic did not reduce yield of soybean planted in wider rows, but non-irrigated soybean planted in 36-inch row spacing yielded equal to or less than trafficked soybean planted in narrow rows. Drilled soybean tended to compensate for damaged rows better than 15-inch soybean, but only when environmental conditions were conducive for compensation. Water stress during the time of traffic treatment reduced soybean's ability to compensate for damaged rows. When prorated to 45- to 120-ft booms, yield loss ranged from 6.4 to 1.0%. These data provide information that can be used to refine reproductive-stage pest management decisions in soybean.

Morphology, forage and seed yield of soybean cultivars of different maturity grown as a forage crop in Turkey

Soybean [Glycine max (L.) Merr.] has long been used as a forage crop but its morphological development and forage potential have not been studied extensively. A study was conducted using oilseed soybean cultivars of different maturity to determine their morphological development, forage yield, seed components and seed yield at the University of Ankara, Turkey. Five soybean cultivars OAC Salem (earliest), OAC Bayfield (midearly), OAC Eclipse (mid-early but later than OAC Bayfield), OAC Glencoe (full-season soybean) and SA.88 (late), were used in the study conducted in 2000 and 2001. The full-season cultivar OAC Glencoe was the tallest cultivar, and had the highest levels of fresh and dry matter yield and crude protein yield among soybean cultivars in both years. Therefore, OAC Glencoe is considered to be the most suitable soybean cultivar for forage production when intercropped with corn in Ankara region of Turkey. However, attention should be given to the earliest maturing cultivar OAC Salem that had the highest seed yield and better relative seed composition of all the cultivars. Key words: Forage, soybean, cultivar, morphology, development

Biosolids application to soybeans and effects on input and output of nitrogen

Abstract A significant portion of biosolids applied to land in Maryland are incorporated into soil planted to soybeans (Glycine max (L.) Merr.). It is generally assumed that nitrogen in biosolids reduces the process of biological N-fixation, although recent evidence suggests that this may not always be true. The objectives of this study were: (i) to determine the fate, plant uptake and cycling within the rooting zone of N derived from biosolids applied to soybeans; (ii) to assess the potential impact of biosolids application to soybeans on groundwater quality; and (iii) to determine the effects of biosolids application on soybean yield. Six field plots (0.3 ha each) were established and one-half of the plots were amended with biosolids to supply 120 kg ha−1 available N. Plots were cropped to full season soybeans and N content of the soil periodically measured. The application of biosolids to soybean was not shown to significantly repress N-fixation. Plants continued to fix nearly normal amounts of N even in the presence of N from biosolids. This resulted in the presence of excessive quantities of N in soil following harvest. When soil was sampled to a depth of 2 m, the NO3-N concentration in the plots amended with biosolids was found to be slightly higher than under the unamended controls. Groundwater NO3-N concentrations were elevated under the biosolids amended plots; however, differences between treatments were rarely significant. It is hypothesized that the excess N under soybeans amended with biosolids may be lost to the atmosphere due to the process of denitrification.

A delayed flowering barrier to higher soybean yields

A long term maximum yield soybean [Glycine max (L.) Merr.] research project was initiated at Wooster, OH (40°N latitude) in 1977 with the specific objectives of determining the yield potential of soybeans and identifying yield limiting factors. Results from this research suggest there is a delayed flowering barrier to higher soybean yields in the higher latitudes where the light intensity (sun angle) is highest and the day length is longest early in the growing season, declining as the growing season progresses. At Wooster, OH, the average 24 h total solar radiation declines from 474 Langleys (cal/cm2) in June to 351 Langleys in September. The maximum daily solar energy declines from 680 Langleys (15–30 June) to 444 Langleys 15–30 September. Under normal spring temperatures in May, soybeans planted during the first week of May normally bloom during the first week of July. However, in 1982, 1985, 1998, and 1999, unusually early warm spring temperatures in May resulted in the soybeans flowering around 15 June, 2 weeks earlier than normal. In a maximum yield environment, where all manageable yield limiting factors were minimized, test average yields were 5963 kg/ha in 1982, 5549 kg/ha in 1985, 5383 kg/ha in 1998, and 5416 kg/ha in 1999, with individual lines producing replicated yields in the 6000–7000 kg/ha range. In the intervening years, 1983 and 1984 and from 1986 to 1997, with more normal spring temperatures, test average yields in the maximum yield environment ranged from 3575 to 4862 kg/ha, with highest yielding individual lines producing yields in the 4200–5500 kg/ha range. These results indicate there is a temperature by photoperiod interaction in soybeans that results in soybeans flowering up to 2 weeks earlier than normal in response to above normal temperatures in early spring (in May at Wooster, OH). This results in the soybeans entering the reproductive cycle earlier in the growing season when the days are longer and the light intensity is higher (greater total solar radiation is available). Also the length of the reproductive cycle was increased since maturity was similar to years of more normal spring temperatures. This resulted in a significant increase in the yield potential of soybeans in years of unusually early warm spring temperatures. These results suggest if breeders can develop full season soybean cultivars that will bloom earlier under more normal spring temperatures, the yield potential of soybeans in the higher latitudes could be significantly increased.

Double-cropping Winter Wheat and Soybean Improves Net Returns in the Eastern Great Plains

In the eastern Great Plains, winter wheat (Triticum aestivum L.) and different soybean [Glycine max(L.) Merr.] maturity groups (MG) are grown in various cropping systems to diversify crop production. A 10-year field study was conducted in southeastern Kansas to evaluate effects of multi-cropping systems on grain yield and net economic returns. Cropping systems evaluated were: (i) annual double-cropping of wheat and soybean (MG IV); (ii) four 2-year rotations of wheat-soybean double-cropped followed by full-season soybean the next year, where the same soybean MG (I, III, IV, and V) was grown both years; and (iii) a 3-year rotation of wheat, wheat, and full-season (MG V) soybean. On average, wheat yields ranged from 51 bu/acre following early MG I soybean in the 2-year double-crop rotation to 36 bu/acre following MG IV soybean in the annual double-cropping system. Wheat yield differences were primarily determined by planting date. Full-season (MG V) soybean yields were highest (35 bu/acre) following two years of wheat in the 3-year rotation. Double-crop soybean yields in the annual double-cropping system averaged 26 bu/acre for MG IV. Full-season and double-crop soybean yields in the 2-year double-crop rotation system were significantly greater for traditional MGs (III, IV, and V) than MG I. Net economic returns averaged $101/acre for annual double-cropping, which was $10 to $25/acre higher than 2-year systems with MGs III, IV, and V; whereas, net returns were lowest for the 3-year rotation ($51/acre) and for the 2-year system with MG I soybean ($44/acre).

Long-Term Variable Rate Lime and Phosphorus Application for Piedmont No-Till Field Crops

Variable rate (VR) fertilizer application is a paradigm with potential to improve input efficiency and farm profitability. It is widely marketed by commercial applicators in the southeastern US. However, field studies comparing VR with traditional management have not demonstrated consistent, positive results. The objectives of this study were: (1) to determine the soil impact, crop response and economic potential of VR phosphorus (P) and lime application in a North Carolina Piedmont no-till field crop system using intensive soybean [Glycine max (L.) Merr.] production and (2) to economically evaluate alternatives to standard commercial grid soil sampling for directing VR P and lime. A 23-ha long-term no-till field in the SE Piedmont was divided into 0.4ha plots assigned to either VR or uniform P and lime application. Grid soil sampling and VR P and lime application were done prior to four crops over 3 years: full season soybean, wheat (Triticum aestivum L.)–double cropped soybean, and full season soybean. Soil test P, pH and crop yield response to VR P were inconsistent. Soil pH in areas with low pH initially did increase in response to VR lime, but it took two to three applications to bring all of these areas to the target pH. Once VR-liming raised initially low soil pH to levels close to target, yield of soybean, but not wheat, were up to 0.74Mg ha−1 higher than with uniform lime. Even with significantly higher soybean yields associated with VR lime, 3 years of grid sampling and VR application were not profitable compared to uniform application. The results indicated that VR lime could be profitable if the initial grid sampling data were used either for 2 consecutive years, or if it was used to restrict future grid sampling to specific areas requiring further VR lime.