Crop rotation is a management practice with high greenhouse gas (GHG) mitigating potential that is often neglected due to economic influences. Three long-term rotation studies in Wisconsin were selected to assess the potential opportunities for mitigating GHG emissions by comparing the temporal and spatial variability of N2 O, CO2 , and CH4 emissions in continuous corn (CC) (Zea mays L.), corn-soybean (CS) [Glycine max (L.) Merr.], and corn-soybean-wheat (CSW) (Triticum aestivum L.) using a static chamber method. GHG emissions were influenced by weather conditions and following nitrogen (N) application during a 3-year measurement period. In high N input environments at Arlington and Lancaster, N2 O emissions in CC were 5.80 and 4.40 kg N ha-1 , respectively, which was much higher than the emissions in CS and CSW rotations that ranged from 1.52 to 3.33 kg N ha-1 . In the low N input environment at Marshfield, N2 O emissions were not statistically different among CC, CS, and CSW rotations (1.20-1.66 kg N ha-1 ). Yield-scaled N2 O emissions were not different among crop rotations. When pooled over locations, CO2 emissions were highest in CC (4.16 Mg C ha-1 ) and were similar in CS and CSW (3.71 and 3.50 Mg C ha-1 , respectively). Soils either emitted or absorbed small and inconsistent amounts of CH4 . These results provide important insights as to how weather conditions and differences among management practices affect GHG emissions and show that application of either 2-year CS or 3-year CSW rotation can be equally effective in reducing N2 O emissions compared to CC, especially with high N applications.

Integrating alfalfa (Medicago sativa L.) with corn (Zea mays L.) for grain will increase biodiversity, reduce the negative environmental impact of corn monoculture and increase farm profitability. The objectives of this research were to evaluate forage productivity and nutritive value, along with stand establishment of alfalfa in a corn grain system in Iowa, Minnesota, and North Dakota. The experimental design was a randomized complete block with four replicates at each site. Treatments included were: sole corn (i.e., check; T1), sole alfalfa (T2), alfalfa intercropped into corn (T3), a prohexadione-treated alfalfa intercropped with corn (T4), and a spring-seeded alfalfa in the year after intercropping (T5), which was planted in plots with T1 the previous year. All sites had below normal rainfall in 2016 and 2017. Corn grain yield was significantly lower when intercropped with alfalfa (T3 and T4) compared with the check corn crop (no alfalfa, T1). Corn grain yield reduction ranged from 14.0% to 18.8% compared with the check (T1). Corn biomass yield was reduced by intercropped alfalfa (T3 and T4) by 15.9% to 25.8%. In the seeding year, alfalfa seasonal forage yield was significantly greater when corn competition was absent in all environments. The intercropped alfalfa from the previous season (T3 and T4) had almost double the forage yield than the alfalfa in the seeding year (spring-seeded alfalfa; T5). In the second production year, there were no meaningful forage yield differences (p > 0.05) across all treatments, indicating alfalfa in intercropping systems does not affect forage yield past the first production year. Prohexadione-calcium, a growth regulator, did not affect alfalfa stand density, forage yield and nutritive value. The forage nutritive value was dependent on harvest date not the alfalfa intercropping treatments. Results of our study suggest that establishing alfalfa with corn is feasible and can be a potential alternative for the upper Midwest region. However, when under drought conditions, this system might be less resilient since competition between alfalfa and corn for soil moisture will be intensified under drought or moisture-limited conditions, and this will likely depress corn grain yield. Research targeted to reintroduce perennial crops into the current dominant corn–soybean systems in the US Corn Belt is urgently needed to improve stability and resiliency of production systems.

The aim of this study was to verify the response of 13 American asparagus cultivars cultivated for green spear on surface postharvest drip irrigation. Irrigation, used to compensate for periodic deficiencies in precipitation, allows for high- and good-quality crops for many species. The field experiment was carried out in 2006–2008 on a very light sandy soil in central Europe (Poland). Irrigation treatments were applied using the tensiometer indications. Water requirements of asparagus were calculated on the base of reference evapotranspiration and crop coefficients. The following evaluations were made: Height, diameter, and number of summer stalks, as well marketable yield, weight, and number of consumption green spears. Drip irrigation applied for 2 years (2006–2007) in the postharvest period had a positive effect on all studied traits in both summer stalks and green spears in 2007–2008. A significant increase in the height, number, and diameter of summer stalks, as well an increase in the marketable yield, weight, and number of green spears was observed for most of the cultivars. In general, postharvest drip irrigation of asparagus cultivated in very light sandy soil significantly contributes to the increase in productivity of American cultivars of this species.

Weather conditions regulate the growth and yield of crops, especially in rain-fed agricultural systems. This study evaluated the use and relative importance of readily available weather data to develop yield estimation models for maize and soybean in the US central Corn Belt. Total rainfall (Rain), average air temperature (Tavg), and the difference between maximum and minimum air temperature (Tdiff) at weekly, biweekly, and monthly timescales from May to August were used to estimate county-level maize and soybean grain yields for Iowa, Illinois, Indiana, and Minnesota. Step-wise multiple linear regression (MLR), general additive (GAM), and support vector machine (SVM) models were trained with Rain, Tavg, and with/without Tdiff. For the total study area and at individual state level, SVM outperformed other models at all temporal levels for both maize and soybean. For maize, Tavg and Tdiff during July and August, and Rain during June and July, were relatively more important whereas for soybean, Tavg in June and Tdiff and Rain during August were more important. The SVM model with weekly Rain and Tavg estimated the overall maize yield with a root mean square error (RMSE) of 591 kg ha−1 (4.9% nRMSE) and soybean yield with a RMSE of 205 kg ha−1 (5.5% nRMSE). Inclusion of Tdiff in the model considerably improved yield estimation for both crops; however, the magnitude of improvement varied with the model and temporal level of weather data. This study shows the relative importance of weather variables and reliable yield estimation of maize and soybean from readily available weather data to develop a decision support tool in the US central Corn Belt.

The effect of nitrogen fertigation of two watermelon cultivars grown on the very light soil in the central part of Poland, during 2012–2014, was evaluated. The field experimental design was a split-plot with four replications. The main plot was the drip fertigation with nitrogen applied in two combinations: drip irrigation + broadcasted nitrogen fertilization (DI) used as a control, and drip irrigation + fertigation with nitrogen (DF); where, two cultivars: Bingo and Sugar Baby were used as a split-plot. The phosphorus and potassium fertilizers were applied pre plant in the spring, whereas, three rates of 40 kg ha−1 of nitrogen fertilizer were applied during the growing season. The fertigation was performed using a proportional mixing dispenser. The ripened fruits were harvested progressively as they mature. The marketable fruit yield, the single fruit weight and the number of fruits per plant, were evaluated. Tested factors presented a significant effect in the yield characteristics, further the interaction among the factors was important. DF, comparing to DI, notably improved fruit traits. Bingo cultivar had higher yield than Sugar Baby, but Sugar Baby cultivar produced more fruits than the Bingo under the DF treatment. This study provides the evidence that on a very light soil with low water and nutrients retention capacity the performance of watermelon can be optimized when nitrogen is applied directly through drip irrigation.

Climate changes lead to a rise in air temperature, which significantly increases the water needs of plants. Maintaining crop productivity will increasingly require the use of plant irrigation. The aim of this study was to assess the water needs of grapevines cultivated in the western provinces of Poland. The calculations were made on the basis of temperature and precipitation measurements collected at three meteorological stations in the period 1981–2010. Water needs were calculated as crop evapotranspiration, which was estimated by crop coefficients and reference evapotranspiration, determined using the Blaney–Criddle formula. The rainfall deficit was assessed by Ostromęcki’s method. The tendency to increase the water needs was observed in each subsequent decade of the thirty-year period, both in the whole growing season (May–October), as well as in June–August and July. The highest values of the linear correlation coefficient for the trend of time variability in water needs occurred from June to August. An analysis of water needs and rainfall deficits indicates the need for the additional irrigation of vineyards in western Poland, especially in very dry years and in June–August. Current research results are helpful in designing vineyard irrigation systems and allow an economical and efficient planning of grapevine irrigation.

Neonicotinoids are the most widely used insecticides worldwide and are typically deployed as seed treatments (hereafter NST) in many grain and oilseed crops, including soybeans. However, there is a surprising dearth of information regarding NST effectiveness in increasing soybean seed yield, and most published data suggest weak, or inconsistent yield benefit. The US is the key soybean-producing nation worldwide and this work includes soybean yield data from 194 randomized and replicated field studies conducted specifically to evaluate the effect of NSTs on soybean seed yield at sites within 14 states from 2006 through 2017. Here we show that across the principal soybean-growing region of the country, there are negligible and management-specific yield benefits attributed to NSTs. Across the entire region, the maximum observed yield benefits due to fungicide (FST = fungicide seed treatment) + neonicotinoid use (FST+NST) reached 0.13 Mg/ha. Across the entire region, combinations of management practices affected the effectiveness of FST+NST to increase yield but benefits were minimal ranging between 0.01 to 0.22 Mg/ha. Despite widespread use, this practice appears to have little benefit for most of soybean producers; across the entire region, a partial economic analysis further showed inconsistent evidence of a break-even cost of FST or FST+ NST. These results demonstrate that the current widespread prophylactic use of NST in the key soybean-producing areas of the US should be re-evaluated by producers and regulators alike.

In the US, the most recent published estimates reflect that approximately 34-44% of planted soybean acreage are treated with neonicotinoid seed treatments (NST) (Douglas & Tooker, 2015). Based upon trendlines shown in that work, the current estimate for NST use in soybeans is very likely to exceed 50%. Insecticidal seed treatments of soybean belong to the neonicotinoid class of insecticides that include the active ingredients clothianidin, imidacloprid, and thiamethoxam. Corn and soybean seed treatments represent the largest uses of neonicotinoids nationally, and the higher seeding rate of soybeans mean that they are responsible for the highest levels of active ingredient per unit area (USGS, 2014). It is notable that current NST use rates far exceed historic benchmarks for insecticide use in soybeans; in the decade prior to introduction of neonicotinoid seed treatments, only about 5% of soybean acres received insecticides (Fernandez-Cornejo et al., 2014). This benchmark reflects that the region where most of US soybeans are grown, the upper Midwest, benefits from a temperate climate and relatively few insect pests, particularly in the early season when NST would provide most crop protection. Recent reviews of insect pest abundance in soybean re-confirm this assessment – early season pests of soybean are still infrequently encountered across the region (Hesler et al., 2018; Papiernik et al., 2018). Soybean aphid, a relatively recent invader to US soybean production, is a notable exception, but it’s distribution and phenology are a poor fit for the earlygrowing season, when NST are most effective (Krupke et al., 2017).

Abstract: Intercropping winter cereals into Kura clover (Trifolium ambiguum M. Bieb.) has the potential to improve forage nutritive value without reducing yields. The objective of this research was to compare forage yield and nutritive value of cereal–legume mixtures to cereals or Kura clover grown in monoculture and harvested at two different maturity stages in spring. Winter rye (Secale cereale L.), winter wheat (Triticum aestivum L.), and winter triticale (×Triticosecale Wittmack) were sown in autumn at two locations as monocultures and into herbicide suppressed and non-suppressed Kura clover and harvested for forage the following spring. Harvested at the cereal crop boot stage at Arlington, forage yields averaged 4.7, 4.8, 5.3, and 1.7 Mg ha-1 and 3.5, 3.7, 4.1, and 2.6 Mg ha-1 at Lancaster for mixtures with non-suppressed Kura clover, suppressed Kura clover, monoculture cereals, and monoculture clover, respectively. At the milk stage, yields across all mixture treatments increased by 46% to 115% compared to the boot stage at Arlington and by 88% to 101% at Lancaster. Kura clover in mixtures increased crude protein by 34% to 46% and in vitro true digestibility by 3% to 6%, neutral detergent fiber digestibility by 0% to 6%, and reduced neutral detergent fiber concentration by 8% to 18% relative to cereal monocultures. The nutritive value of mixtures and monoculture Kura clover was always greater than that of monoculture cereals. Winter cereals can be successfully managed with Kura clover for forage production by maximizing nutritive value with boot stage harvests or achieving higher yields by harvesting at the milk stage.

ABSTRACT The nutritional value of carrot is determined by the content of total sugars and monosaccharides, carotenoids and vitamins, including vitamin C, in its roots. In 2009-2011, field experiments were carried out concerning the effect of biostimulating preparations applied during the carrot vegetation period on selected nutrients of its roots (total sugars, monosaccharides, carotenoids and vitamin C). Two biostimulants were foliarly applied in doses of 2 or 3 L ha-1 on various dates. Kelpak SL and Asahi SL: one, two or three applications; where, second and third applied at 2-week interval, additionally Kelpak SL: one application at 4-leaf phase, followed by additional application after 4 weeks. The field study was conducted in a randomized block design with four replications. The treatments of plant protection from diseases and pests complied with carrot requirements. The subject of the research was carrot of the Karotan cultivar. The content of selected components in carrot roots was determined directly after harvest and after six months of storage in the storage chamber with controlled temperature and relative air humidity. The foliar application of Kelpak SL in a single dose (2 L ha-1) at 4-leaf development phase resulted in the significant increase of total sugars, reducing sugars, total carotenoids and vitamin C. A six-month storage period resulted in a decrease of total sugars by 5% and ascorbic acid by 16.8% compared to nutritional values measured right after harvest.

Asparagus (Asparagus officinalis L.), due to their deep and well-developed root system, are relatively resistant to the water deficits in the soil. On the other hand, asparagus plants grown on the light soil positively respond to the irrigation treatments. The aim of the present study was the determination of water needs of asparagus plants in the different agro-climatic regions of Poland. The calculations of asparagus water requirements, considered as the crop evapotranspiration, based on the precipitation measurements collected during the thirty-year period from 1981 to 2010. The estimations were achieved for the months, including July and August, critical in terms of the amount of water available to the plants. The calculation of asparagus water needs using the plant coefficients was performed. The plant coefficients for asparagus cultivated in the Polish field conditions were determined by Rolbiecki. Published by him calculations based on the long term observations of the irrigated asparagus crop. The reference evapotranspiration was calculated according to Grabarczyk's method. The Grabarczyk's formula was chosen because it allowed estimating the reference evapotranspiration in a simplified way, i.e. based only on the precipitation measurements. The rainfall deficit was considered using the Ostromecki's method. The precipitation deficit in the period from July 1 to August 31 was calculated as the difference between the water needs of asparagus, expressed as the crop evapotranspiration for a considered month and the total precipitation in this month. The water needs of asparagus plants were determined for five agro-climatic regions of Poland with the representative meteorological stations located in Olsztyn, Bydgoszcz, Warszawa, Wroclaw and Krakow. The highest variability of asparagus water requirements was calculated in the central-north-west (C-N-W) region of the Poland. The variation coefficient in July and August was 7.7% and 7.6%, respectively. In contrast, the lowest variability of asparagus water needs were find in the south-west (S-W) and south-east (S-E) region of Poland. The highest water needs of asparagus plants, on average 228 mm, in the period from July to August were noted in the C-N-W and central-east (C-E) region of Poland. The highest rainfall deficit, calculated for medium dry years, average dry years and very dry years, was 91 mm and 89 mm, 157 mm and 166 mm, and 209 mm and 245 mm, respectively, in the C-N-W and C-E region, respectively. Generally, higher precipitation deficiencies were noted in August than in July.

Soybean [Glycine max (L.) Merr.] produces a high‐quality protein that provides an appropriate balance of amino acids for monogastric animals. It has been reported that the relative abundance of some essential amino acids may be reduced in soybean with high protein concentration. A dilution of essential amino acids in soybean protein would lead to a reduction in the value of that protein to the end user, and undefined variation in amino acid balance of soybean would lead to poorly balanced animal rations. The objective of this work was to determine whether amino acid balance is affected by seed protein concentration and to characterize any putative changes in the relative abundance of each amino acid across a range of soybean protein concentrations. We created a wide range of protein concentrations in soybean seed by imposing managed stress treatments previously shown to lower or raise protein concentration. We found that the amino acid composition of soybean protein was affected by protein concentration. The relative abundance of amino acids that are often limiting for animal growth, such as lysine, methionine, cysteine, tryptophan, and threonine, were reduced with increasing seed protein concentrations, whereas arginine and glutamic acid were increased. However, treatments used in this study uncovered a potential role for the availability and source of reduced C and N to impact the relative abundance of each amino acid independently, highlighting the complexity of this interrelationship.

The effect of post-harvest irrigation and genotype on the quality components of white asparagus spears was investigated. The field experiment was conducted in 2003-2008 on a very light soil in the Bydgoszcz region. The research was based on a two-factorial split-plot design with randomly selected sub-main blocks. The first studied factor was irrigation applied as two treatments: drip irrigation and microsprinkler irrigation. Non-irrigated plants were tested as the control. The second factor considered was genotype represented by three male cultivars of the garden asparagus: ‘Gijnlim’, ‘Ramos’ and ‘Vulkan’. The irrigation started after the harvest of the spears, while the concentrations of chemical ingredients were measured in the white spears collected in the next growing period. The level of the tested components was significantly influenced by both factors studied. The average amounts of dry matter, potassium, iron and nitrates measured in the white spears were 6.37%, 268.9 mg 100 g−1 f.m., 0.29 mg 100 g−1 f.m. and 62.1 mg kg−1 f.m., respectively. Compared to the control, both irrigation treatments considerably increased the dry matter and potassium contents. The irrigation reduced the amount of nitrates, although the microsprinkler irrigation gave better results than the drip irrigation. The highest concentrations of potassium and iron were measured in the spears of ‘Ramos’, especially in the case of drip-irrigated (potassium) and non-irrigated (iron) plants. The amount of dry matter was high in the spears of ‘Ramos’, while ‘Vulkan’ presented a low tendency to accumulate nitrates.

Agriculture in the Midwest region of the United States is based on intensive corn (Zea mays L.) production that provides food, feed, and fuel. Crop rotation is a vital management option for improved yield and environment preservation. Three rotation systems-continuous corn (CC), corn-soybean (Glycine max [L.] Merr.; CS), and corn-soybean-wheat (Triticum aestivum L.; CSW)-were selected to study their effects on grain yields and carbon (C) and nitrogen (N) accumulation and partitioning within corn grain, stover, and cob plant components. The experiment was conducted at three pre-established crop rotation experiments located at three sites in Wisconsin. Biomass sampling was performed in four consecutive years (2011 to 2014). Analysis of variance showed differences in location for most variables, an effect of crop rotation on stover biomass and stover C, and an interaction effect between location and rotation on soybean grain yield. Averaged across years and locations, final corn and soybean grain yield increased with rotation complexity where corn in the CSW rotation had 15% and 8% greater yield than CC and CS rotation, respectively. Overall, the biomass distribution among corn plant parts was 52%, 41%, and 7% for grain, stover, and cob, respectively. Stover and cobs harvested from corn grown in monoculture produced approximately 11% (0.54 Mg C ha(-1)) less C than corn grown in either CS or CSW rotation. Across rotations, the accumulation of N in plant tissues was not significantly different. However, these results show that crop rotation can increase grain yield and biomass C and partially offset the difference in soil C, which is expected to be greater under CC.

Traditionally, perennial grasses are planted as permanent forage for livestock production, offering additional ecosystem services such as reduced soil erosion, greenhouse gases mitigation, and wildlife habitat. With the new technologies perennial grasses can be transformed and used as biofuel crops. In this context, the objective of this work was to determine the yield potential and biomass quality of 12 different perennial grasses, under rain-fed conditions in Fargo, ND. The highest yielding species was tall wheatgrass (Thinopyrum ponticum) at 11.3 Mg.ha-1 dry matter, and the lowest yielding species was little bluestem (Schizachyrium scoparium) at 4.0 Mg.ha(-1) DM. Biomass quality varied among grasses and harvest date. Generally, ash content was higher in the second harvest. Lignin content was similar between cuts except in western wheatgrass (Pascopyrum smithii). Hemicellulose content was higher in the first harvest for both smooth bromegrass (Bromus inermis) and meadow bromegrass (Bromus biebersteinii). Cellulose content was generally higher in the second cut for most species, with the exception of sideoats gramma (Bouteloua cutipendula) and intermediate wheatgrass (Thinopyrum intermedium) which were higher in the first cut. Nitrogen uptake was similar among all grasses in both harvests, but lower in the second harvest. The gross calorific value (GCV) was higher in the second harvest only in reed canarygrass (Phalaris arundinaceae) and orchardgrass (Dactylis glomerata).

W USA lucerna zajmuje wśród roślin rolniczych czwarte miejsce pod względem powierzchni uprawy. Hodowla nowych odmian ma na celu zwiększenie odporności na patogeny i suszę, a także poprawę jakości paszy przy zachowaniu wysokiego poziomu plonowania. Na etapie testów jest genetycznie modyfikowana (GM) odmiana lucerny o obniżonej zawartości lignin. Dostępna jest też podobna odmiana, ale uzyskana metodami konwencjonalnymi. Oceniana jest przydatność gatunków i odmian traw do dwuskładnikowych mieszanek z lucerną, w tym odmian lucerny o obniżonej zawartości lignin. Rozpoczęto badania nad wykorzystaniem urządzeń teledetekcyjnych do monitorowania jakości paszy podczas wegetacji lucerny. Wprowadzenie do uprawy odmian lucerny odpornych na glifosat daje możliwość wsiewania ich w kukurydzę. Opracowano matematyczny model oceniający prawdopodobieństwo rozprzestrzeniania się genu warunkującego odporność na glifosat, co ma umożliwić koegzystencję odmian konwencjonalnych i GM. Podstawowymi zadaniami w zakresie zwiększenia znaczenia koniczyny jest wydłużenie okresu użytkowania koniczyny czerwonej oraz rozszerzenie areału uprawy koniczyny kaukaskiej.

In response to climate change, there is a need to adopt more resilient cropping systems for increased productivity. In this study, three corn (Zea mays L.)-based rotations—continuous corn (CC), corn–soybean (Glycine max [L.] Merr.; CS), and corn–soybean–wheat (Triticum aestivum L.; CSW), where all residues were retained on the field after harvest—were selected to study their effects on soil properties at three managed sites in Wisconsin—Arlington, Lancaster, and Marshfield. Soil core samples were collected at four depths (0 to 10, 10 to 20, 20 to 40, and 40 to 60 cm) in 2011. In 2013 and 2015, soil core samples were collected at the two top depths. Soil water retention (WR), plant available water (PAW), bulk density (BD), soil carbon (C), soil nitrogen (N), and C/N ratio were evaluated. Water retention was determined from 0 to 10 and 10 to 20 cm depths at five different matric potentials (Ψ = 0, −5, −10, −33, and −1,500 kPa). There was a significant location × depth interaction across soil properties, which could be associated with differences in management among locations. Averaged across location, CC and CSW rotations had greater water content and PAW across WR tensions than CS rotation at 0 to 10 cm depth, while no differences existed at 10 to 20 cm depth. Crop rotations had similar BD across locations and depths (1.37 to 1.41 g cm−3). A significant three-way location × depth × rotation interaction for C and N amount was affected with generally higher C and N amount in CSW rotation at Lancaster and smaller differences among crop rotations at Arlington and Marshfield. Observed low soil C/N ratio values (<11) indicated potential for soil organic matter to provide some N to the crop. Results from this study indicate that long-term CC systems had similar soil properties to those found in the CS and CSW rotations, and differences among locations were attributed to the differences in management and the environments. However, there is a potential for higher WR under CSW rotation, which might be important under variable climatic conditions.