Soil compaction is a major factor which influences root growth and crop yields. Studies were conducted to determine the influence of different factors on mechanical impedance and to determine the influence of mechanical impedance and other soil factors on root growth. Regression models for dependent variables, soil strength and root growth, vs. the independent variables, soil type, soil depth, clay content, bulk density, voids, and water content were computed using the maximum R2 improvement by stepwise regression. The models for soil strength and root growth varied with soil type, soil depth, and/or clay content. The soils used were a Miles fine sandy loam, Udic Paleustalf and an Abilene clay loam, Pachic Argiustoll. Soil strength for both soils studied and at all depths was influenced by bulk density, voids, and clay content. The overall equational models accounted for 75% of the variability in soil strength and 76% of the variability in root growth. Root growth in both soils and at all depths was significantly influenced by soil strength, volumetric water content, voids, and clay content. The critical strength in bars, defined as the probe pressure at which root elongation stopped, was a function of % clay. The critical strength ranged from 60 to 70 bars in coarsetextured to 25 bars in clay soils. These data provide a better understanding of the influence of mechanical impedance on root growth, and a basis for determining the need for use of deep tillage to minimize the adverse effects of excessive soil strength or compaction.

Protein quality of soybean [Glycine max (L.) Merr.] seed could be enhanced by increasing the concentration of S‐containing amino acids. The N:S ratio of soybean seed tissue is an indicator of protein quality. The objective of this study was to compare N and S accumulation and distribution in the soybean plant under varying levels of S availability. Soil S levels were varied in two greenhouse trials and tissue S and N contents were monitored. A field experi~nent with 0 and 60 kg ha−1 applied S was also conducted. In the two greenhouse trials, seed yield, rate of dry matter increase, and rate of N accrual by shoots all increased at least five‐fold as S availability increased from less than 15 (zero added S) to 60 mg available S per plant, but showed little response to higher levels of S. Rate of S accrual was strongly related to S availability. In the field trial, there were no responses to added S. Leaf, pod, and seed tissue appeared to accumulate S in proteins, whereas, root and stem tissue appeared to accumulate S as sulfate. Harvest index values for S were consistently less than those for N, indicating S is not remobilized to seed as efficiently as is N. Seed S:N ratio was linearly related to the rate of S versus N accrual on a whole‐plant basis. We estimate that a 50% increase in the amount of S‐containing amino acids in soybean seed may require a 65 to 80% increase in S accrual by shoots to satisfy the increased demand for S.

Integrated crop–livestock systems (ICLSs) can help increase food production while benefiting soils and the environment. This review summarizes recent impacts of ICLSs on crop and livestock production and rural economics and discusses lessons learned in the northern Great Plains (NGP). Research on ICLS conducted in the NGP indicates that the crop residue grazing, swath grazing, and annual forage grazing can positively influence crop production; whereas, livestock performance varies with season, forage nutritive value, and grazing management. Furthermore, ICLSs can reduce the costs and risks of agricultural production. The success of ICLSs in NGP region depends on trade‐offs, planning, economic benefits, policies, regulations, community acceptance, and management skills. The ICLSs could play a strategic role in future agricultural production. The lessons learned from adopting ICLSs in the NGP include the lack of available land for fertilizer (manure) management, that to implement ICLS practices skills and knowledge must be maintained, and ICLS provides an entry point for young farmers and ranchers however capital is needed. These experiences and lessons could be valuable references for producers to adopt ICLSs in the NGP or other regions. Core Ideas Integrated crop–livestock systems positively affect crop production by improving soil health. Common integrated crop–livestock system management techniques can enhance the northern Great Plains crop production. Integrated crop–livestock system livestock performance is impacted by season, forage selection, and management. Integrated crop–livestock systems can increase economic benefits and reduce economic risks. Experiences and lessons in the northern Great Plains could be valuable for other regions to adopt integrated crop–livestock systems.

The nutritional value of soybean [Glycine max (L.) Merr.] seed protein could be enhanced by increasing its concentration of the S‐containing amino acids, methionine and cysteine. Two greenhouse pot studies and one field study were conducted with soybean grown under varying levels of S availability to observe the relationship between S availability, seed S content, and relative abundance of poor and high quality storage proteins. Abundances of the [β‐subunit of β‐conglycinin (poor quality) and of glycinin (high quality) seed storage proteins were determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Cotyledon‐S concentration more than doubled, and the N:S ratio of the seed decreased sharply (from about 40‐20 g N g S−1), as S availability increased from 12 to 62 mg available S per plant in the first greenhouse trial. The amount of the poor‐quality [β‐subunit of β‐conglycinin was linearly related to the N:S ratio of cotyledon tissue and varied from less than 15 up to 40% of storage proteins. On the other hand, the high‐quality glycinin fraction of storage protein showed a linear, negative relation to N:S ratio of cotyledon tissue and decreased from 60 to less than 30% of storage proteins as the N:S ratio increased under S stress. Even in high S environments the β‐subunit of β‐conglycinin comprised 10% or more of total storage proteins. Since poor quality storage protein was synthesized even in high S environments, we hypothesize that the plant's ability to reduce sulfate and synthesize S‐containing amino acids during seed filling may be a factor limiting soybean protein quality.

Tuber color and appearance are important factors that influence consumer decision-making. In order to evaluate which factors are important to consumers in Maine, we surveyed 275 people over 2 years and four locations to assess fresh potato consumption patterns and to determine how specific potato characteristics influence variety selection. A majority of the study participants were women between the ages of 41 and 60. Over 60% of survey participants cooked and consumed fresh potatoes between one and three times per week, and over 84% of participants reported that baked, mashed, or roasted potatoes were their preferred methods of preparing fresh potatoes. Over 96% of survey participants expressed that potatoes were a healthy food, although more than a third stated that they limited their carbohydrate consumption. The most important potato characteristics found to influence fresh potato purchase were skin quality and place of origin with 30% and 41% of participants giving each of these factors the highest possible score. Participants appear to recognize the importance of the industry, and many expressed interest in buying locally grown potatoes. Skin quality was the most important characteristic influencing preference for whole white and yellow skin varieties (seven of eight varieties) evaluated in the study. Skin quality also influenced variety selection of whole red skin potatoes in five of eight varieties. This suggests that more research is needed to develop varieties and production methods that produce attractive blemish-free potatoes. When participants could see the potato flesh, it significantly influenced variety selection with all potatoes. Flesh color was the most important characteristic of halved potatoes with 13 of 14 possible varieties. Pictures showing potato flesh color may also help retail sales of table stock varieties. The yellow fleshed varieties with white and purple skins were quite popular, but yellow flesh, red skin varieties were less popular.

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Integrated crop-livestock system (ICLS) is an alternative that can help in intensifying food production while benefiting the environment. However, the assessments of the impacts of ICLS on the soil and economic benefits relative to specific environments in South Dakota are still lacking. This study was to assess the effects of ICLS on soil health and economic benefits under a corn (Zea mays L.)-soybean (Glycine max L.)-rye (Secale cereale L.) rotation in South Dakota. Cover crops blends were planted after the rye crop, and grazing treatments (with and without) were applied after the cover crops establishment in 2015-2016. Data from this study indicate that most soil properties are not negatively impacted by grazing. However, the grazing increased soil bulk density (BD) and decreased soil organic carbon (SOC) and soil water retention (SWR) compared with the ungrazing. The effect of grazing on corn yield was not significant. The cover crops did not impact the pH, electrical conductivity (EC), total nitrogen (TN), β-glucosidase, acid hydrolysis carbon fraction, microbial biomass carbon, and SWR, but impacted the SOC, hot/cold water carbon fraction, BD, infiltration rate (q s) in some phases and depths. The effects of different cover crop blends on corn yield were not as strong. The economic analysis showed that implementing ICLS

Cultivar seed size and yield potential of common bean (Phaseolus vulgaris L.) are negatively associated. Large‐seeded cultivars are predominately of Andean background, while small‐seeded cultivars are predominately of Mesoamerican background. Crop growth analyses were conducted to examine the association of cultivar seed size with crop growth rate (CGR), seed growth rate (SGR) on a land‐area basis, intensity of partitioning to seed (land‐area SGR divided by CGR), and effective seed‐filling period. Sixteen cultivars, ranging in seed size from 190 to 540 mg seed−1, were grown at two sites in Colombia at elevations of 1000 m (warm) and 1800 m (cool). The seed size groups did not differ in CGR at either site. At the warmer site, the small‐seeded Mesoamerican lines had greater mean partitioning to seed (1.29 vs. 0.97 for the Mesoamerican and Andean lines, respectively), greater land‐area SGR (11.7 vs. 8.3 g m−2 d−1), and higher yield ( 2030 vs. 1750 kg ha−1) than did the large‐seeded Andean lines. At the cool site, the seed size groups did not differ in any of these variables. At both sites, the Mesoamerican lines flowered ≈6 d later and acquired more total N than did the Andean lines. It is postulated that the greater land‐area SGR and yield of the Mesoamerican lines at the warmer site was due to their greater accumulation of N, which allowed them to sustain greater rates of canopy photosynthesis during seed‐filling.