Winter Small Grain Research Articles

Double cropping and manure management mitigate the environmental impact of a dairy farm under present and future climate

CONTEXTStrategies are needed to reduce the environmental impacts of dairy farms, and these may become more important as our climate continues to change. Double cropping small grain and corn silages provides a strategy that can benefit dairy farms in the northeastern U.S. as they adapt to a longer growing season. Subsurface application of manure may also reduce nitrogen (N) and phosphorus (P) losses as the region faces warmer temperatures and greater precipitation. OBJECTIVEEvaluate whole-farm production, environmental and economic impacts of adopting these strategies on a representative dairy farm in central Pennsylvania under recent historical and projected midcentury climate. METHODSFarm management strategies were simulated using the Integrated Farm System Model to determine effects on crop yields, feed production, volatile, leaching and denitrification losses of N, sediment erosion, sediment-bound and soluble losses of P, farm-gate life cycle greenhouse gas emissions, fossil energy use, and production costs. RESULTS AND CONCLUSIONSDouble cropping increased and stabilized feed production by providing forage from a winter rye crop with less dependency on the summer crops of corn silage and perennial grasses. Summer crops are susceptible to summer droughts, which are expected to increase in this region due to warmer temperatures and increased evapotranspiration. Double cropping was more beneficial in the midcentury climate due to the projected increase in growing season length. Double cropping and subsurface injection of manure reduced total N losses by 12–18% and total P losses by 16–19%. Double cropping using broadcast manure application had a neutral environmental and economic impact on the farm. Adoption of these strategies provided a feasible adaptation and mitigation approach for future climate by reducing projected increases in soluble P runoff and ammonia emission caused by warmer temperatures and greater precipitation while maintaining and potentially reducing total farm production costs. SIGNIFICANCEWhole-farm simulation provides a tool for evaluating potential benefits and tradeoffs of novel technologies and strategies as agriculture adapts to changes in climate. Although these results are specific to a dairy farm in central Pennsylvania, they generally apply to dairy farms throughout the Northeast U.S. and climates where similar changes in temperature and precipitation are projected by mid-century. Our analyses suggest that use of a more intensive crop rotation (double cropping winter small grain and corn silage) along with improved manure application technology (subsurface injection) can help mitigate dairy farm environmental impacts now and even more in the future.

Winter Wheat (Triticum aestivum L.) Tolerance to Mulch.

Mulch from cover crops can effectively suppress weeds in organic corn (Zea mays L.) and soybean (Glycine max L.) as part of cover crop-based rotational no-till systems, but little is known about the feasibility of using mulch to suppress weeds in organic winter small grain crops. A field experiment was conducted in central NY, USA, to quantify winter wheat (Triticum aestivum L.) seedling emergence, weed and crop biomass production, and wheat grain yield across a gradient of mulch biomass. Winter wheat seedling density showed an asymptotic relationship with mulch biomass, with no effect at low rates and a gradual decrease from moderate to high rates of mulch. Selective suppression of weed biomass but not wheat biomass was observed, and wheat grain yield was not reduced at the highest level of mulch (9000 kg ha−1). Results indicate that organic winter wheat can be no-till planted in systems that use mulch for weed suppression. Future research should explore wheat tolerance to mulch under different conditions, and the potential of no-till planting wheat directly into rolled-crimped cover crops.

Coleoptile length comparison of three winter small grain cereals adapted to the Great Plains

Successful crop stand establishment is critical to realize high yield potential, which is dependent on depth of seed placement to access soil moisture. The coleoptile determines sowing depth by its length and ability to emerge from depth. This study was conducted to assess coleoptile length among three sets of three Great Plains winter small grain cereals—wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and triticale (X triticosecale Wittm.)—and to evaluate the effect of the Rht-B1b dwarfing allele on coleoptile length in wheat and triticale. Fifty seeds of each genotype were sown in wet germination paper in two replications utilizing a randomized complete block design, which were placed in dark growth chambers at 25°C. Measurements were conducted after 7 d, and analysis of variance and comparison of least square means for coleoptile length among and within each set of genotypes were performed in Statistix 8.1 software using Fisher’s protected least significance difference at the α = 0.05 significance level. Results revealed that triticale had the longest coleoptiles, which were significantly longer (P < 0.05) than those measured in both barley and wheat. Additionally, significant variation in coleoptile length (P < 0.05) was also found within each set of wheat (3.52–6.41 cm), barley (4.32–6.63 cm) and triticale (4.05–6.92 cm) genotypes, respectively. These findings confirm other reports that the presence of the Rht-B1b allele was pleiotropic for coleoptile length, but development of semi-dwarf wheats with longer coleoptiles is possible if breeders deploy concurrent selection strategies.

Potential impact of climate changes in the field crops production

There is evident stagnation or decline in grain yield, as well as high variability in yields, depending on the environment in many countries in recent years, including Serbia and the Republic of Srpska. The causes of this variation were mainly due to the variation of the climatic factors, the onset of drought and the rise in temperatures. Expected changes and especially negative ones will most likely be reflected in the agriculture of southern Europe, especially the Mediterranean, and yield of main field crops. The most negative effects in the area of the continental climate will be in the Pannonian Region which includes Serbia, Croatia, Hungary, Bulgaria and Romania, R. Srpska as a part of Bosnia and Herzegovina. This area will be affected by more frequent waves of heat and drought, with no greater possibility of avoiding by shift of sowing time or other cropping measures. Based on a detailed analysis of climatic factors in the multy-annual period it can be emphasised that some changes in terms of temperature and precipitation occurred. The causes of drought mainly come from the atmosphere and affect our country and show clearly that the climate is changing in our area. Based on these facts, we must have the right answers in order to mitigate if not to completely eliminate these effects. Agronomic aspect of looking into the problem requires a good knowledge of our crop needs for primary vegetative factors as well as temperature and moisture. Annual air temperatures in the investigated period increased not only at the annual level, but also in the vegetative period of winter wheat and particularly maize. The temperature increase is particularly dangerous in the vegetative period of maize during the three months of June, July and August by almost 2 °C. Precipitations at a monthly level of the vegetative period or a total per year do not provide such a picture. Besides the lack in July, normally the warmest month, by and large, precipitations are somewhat higher than the reference 30-year period 1971-2000. This fact tells us that precipitations are more frequent in other parts of the year, which is more favourable for winter small grain cereals,at least when regarding warmer years (especially in the wet years as it is known in the case of extremely wet 2010 yr when it was vice versa). A man can hardly influence the quantity and distribution of rainfall, therefore his actions to combat drought are mainly of indirect character. This comprises a good knowledge of the problems and prediction. For this, we need a lot of knowledge of agronomy, genetics, ecology, physiology, and relevant technical and economic possibilities. If we start from the assumption that the main goal is to provide sufficient and safe quantities of food for our population, then we need to focus on what we have in our hands and begin with it. In the fight against drought, regular and specific cultivation practices are used along with an adequate assortment of crops with more tolerance to drought. Out of regular practices, soil tillage, particularly conservation tillage, proper fertilization, elimination of all possible mistakes in sowing should be taken into account as for optimal time and plant density. Care treatments are a useful tool which can eliminate the adverse effects and create favourable conditions for the growth and development of cultivated crops, ranging from the usual ones to some special ones that retain moisture and prevent moisture loss by encouraging its more efficient and economical use. Appropriately established crop rotations with greater diversification of crops provide better tolerance of extreme moisture, which is particularly the case of winter wheat. Our research shows inferiority of continuous cropping of both crops compared with different crop rotations. However, when comparing crop rotations with each other then it can be noticed that the proper setting, even under extreme conditions, provides better results. As for maize it is evident that all increases of moisture are suitable for it as it is related to the warmer part of the year, either as direct rainfall during the summer or indirectly if the reserve is provided from a period when there are more precipitations during the autumn, winter and spring. Moisture improves the efficiency of all other cultivation practices. In the case of its extended absence followed by high temperatures it is quite the opposite.

Кomparativna analiza gajenja ozimih strnih žita u organsкoj i кonvencionalnoj proizvodnji

Кomparativna analiza gajenja ozimih strnih žita u organsкoj i кonvencionalnoj proizvodnji

Double cropping effects on forage yield and the field water balance

Double cropping is an option to increase feed production from a unit of land. However, summer crop yields may be depressed due to shortened length of growing season and elevated drought risk. We studied the effect of double cropping winter small grain silage crops (rye, Secale cereale L. and barley, Hordeum vulgare L.) on corn (Zea mays L.), soybean (Glycine max L.), and annual silage yields and soil water balance in no till and compared that with alfalfa (Medicago sativa L.). Precipitation, runoff, deep drainage, and soil water content were measured over a two-year period (variable precipitation), and crop evapotranspiration (ETc) was estimated using the Penman–Monteith method. Small grains were planted in the fall after harvest of the main crops. Corn silage and soybean whole-plant yields were not significantly reduced by double cropping, so total annual silage yields increased with double cropping. Double cropping did not reduce runoff or deep drainage and did not affect soil water content compared with single cropping rotations, but alfalfa rotations occasionally generated less drainage and lower soil water contents. The estimated ETc was higher in double than in single cropping systems during the fall and spring seasons due to transpiration by the winter small grain, but our measurements did not confirm these modeled double cropping effects. The water balance showed a likely over-estimation of drainage and possibly ETc. Double cropping offers the potential to increase annual silage yields without affecting the water balance in Southeastern Pennsylvania.

Why tropical sorghum sown in winter months has delayed flowering and modified morphogenesis in spite of prevailing short days

Sowing certain late photoperiod-sensitive tropical sorghum varieties under short-day conditions in November–January in the northern hemisphere can result in a pronounced delay in flowering and prostrate, high-tillering forms similar to the rosettes in winter small-grain cereals. The cause of this phenomenon in sorghum has long been questioned and is often attributed to the effects of low night temperatures during this period. Monthly sowings, from December to March, in greenhouse compartments with two contrasting night temperatures and under field conditions with contrasting soil conditions were conducted over two years near Bamako, Mali, with three contrasting sorghum varieties. Dates of panicle initiation, rates of leaf primordia initiation at the stem apex, and rates of leaf appearance were observed. In the greenhouse, colder night temperatures were found to have no effect on prolonging vegetative-phase duration when measured in thermal time and on plant development. Although a prolonged vegetative phase and prostrate forms were observed under field conditions, these were not observed in the greenhouse experiments despite having similar temperature conditions. Although the higher soil fertility of the potting soil increased the development rates slightly, and reduced the vegetative phase relative to natural soil conditions in the field, this difference between greenhouse and field growth remained when a comparison was made between plants grown in pots. Thus, it appears that the greenhouse glass had masked the UV component of sunlight, which would mediate the cue responsible for the delayed flowering and modified morphogenesis. This cue, which has strongly contrasting effects between October and November sowings, could be the daily changes in the sunrise and sunset hour that have negative values from November to July.

Soil nitrogen response to coupling cover crops with manure injection

Coupling winter small grain cover crops (CC) with manure (M) application may increase retention of manure nitrogen (N) in corn (Zea mays L.), -soybean [Glycine max (L.) Merr], cropping systems. The objective of this research was to quantify soil N changes after application of liquid swine M (Sus scrofa L.) at target N rates of 112, 224, and 336 kg N ha−1 with and without a CC. A winter rye (Secale cereale L.)-oat (Avena sativa L.) CC was established prior to fall M injection. Surface soil (0–20 cm) inorganic N concentrations were quantified every week for up to 6 weeks after M application in 2005 and 2006. Soil profile (0–120 cm in 5, 20-cm depth increments) inorganic N, total N, total organic carbon and bulk density were quantified for each depth increment in the fall before M application and before the CC was killed the following spring. Surface soil inorganic N on the day of application averaged $$ 318\,{\text{mg}}\;{\text{N}}\;{\text{kg}}^{ - 1}{_{\text{soil}}} $$ in 2005 and $$ 186\,{\text{mg}}\;{\text{N}}\;{\text{kg}}^{ - 1}{_{\text{soil}} }$$ in 2006 and stabilized at $$ 150\,{\text{mg}}\;{\text{N}}\;{\text{kg}}^{ - 1}{_{\text{soil}}}$$ in both years by mid-November. Surface soil NO3-N concentrations in the M band were more than 30 times higher in the fall of 2005 than in 2006. The CC reduced surface soil NO3-N concentrations after manure application by 32% and 67% in mid- November 2005 and 2006, respectively. Manure applied at 224 kg N ha−1 without a CC had significantly more soil profile inorganic-N (480 kg N ha−1) in the spring after M application than manured soils with a CC for the 112 (298 kg N ha−1) and 224 (281 kg N ha−1) N rates, and equivalent inorganic N to the 336 (433 kg N ha−1) N rate. These results quantify the potential for cover crops to enhance manure N retention and reduce N leaching potential in farming systems utilizing manure.

Enhancing Nutrient Cycling by Coupling Cover Crops with Manure Injection

Coupling winter small grain cover crops (CC) with liquid manure injection may increase manure nutrient capture. The objectives of this research were to quantify manure injection effects using target swine (Sus scrofa) manure N rates of 112, 224, and 336 kg N ha−1 on CC plant density, fall and spring shoot biomass, N, P, and K uptake and subsequent corn (Zea mays L.) yield. A winter rye (Secale cereale L.)–oat (Avena sativa L.) CC was established before fall manure injection. Manure injection lowered mean CC plant density 25% because of CC mortality in the injection zone. Fall CC dry matter (DM) was 26% lower in the manure treatments than the no manure CC control, although no difference was detected for N (9.4 kg ha−1) or P (1.4 kg ha−1) uptake. No difference was detected for spring DM between CC no manure and manure treatments. Shoot DM, N, P, and K uptake increased 29, 41, 31, and 25% from the CC manure 112 to CC manure 224 with no increase above CC manure 224. Cover crop N uptake was higher in CC manure vs. no manure (60.1 vs. 35.6 kg ha−1). Cover crop P and K uptake were also higher in CC manure vs. no manure (9.2 vs. 6.6 kg P ha−1 and 41.3 vs. 30.0 kg K ha−1). Corn grain yield was unaffected by CC and responded positively to manure application (11,022 with manure vs. 9,845 kg ha−1 without manure). Coupling manure injection and cover crops can increase nutrient capture without lowering corn yield.

Mixtures of Kura Clover with Small Grains or Italian Ryegrass to Extend the Forage Production Season in the Northern USA

Kura clover (Trifolium ambiguum M. Bieb.) has demonstrated excellent persistence in the northern USA but initiates dormancy earlier in autumn and breaks dormancy later in spring than other adapted legumes. The objective of this study was to determine if combinations of kura clover and small grains or ryegrass (Lolium multiflorum Lam.) could extend the production season for high quality forage in autumn and spring. The study was conducted from 1998 to 2000 in Arlington and Lancaster, WI. Oat (Avena sativa L.), barley (Hordeum vulgare L.), winter wheat (Triticum aestivum L.), winter rye (Secale cereale L.), and Italian ryegrass, were sown in August in monoculture and in binary mixtures with previously established kura clover. In autumn, monoculture kura clover and all mixtures had similar forage yield, but 1.5 Mg ha−1 lower yield than monoculture oat. In spring, binary mixtures of kura clover with winter wheat or winter rye yielded 0.88 Mg ha−1 more than monoculture kura clover. In spring, mixtures with winter wheat or winter rye contained about 60% kura clover. Binary mixtures and monoculture kura clover had 35% greater crude protein, similar in vitro true digestibility, and 32% lower neutral detergent fiber than monoculture small grains and ryegrass in autumn and spring. Oat, barley, or ryegrass sown into kura clover in autumn provide no yield advantage over monoculture kura clover. Winter small grains sown into kura clover in autumn increased forage yield in early spring, but had no impact on full‐season production compared with monoculture kura clover. Ryegrass did not affect spring yield, but did increase full‐season production by 15% compared with monoculture kura clover. Winter small grains and ryegrass can successfully be sown into monoculture kura clover in autumn without the use of herbicides and can increase early spring or total season forage production the following year.

Small grain winter cover crops for conservation of residual soil nitrogen in the mid-Atlantic Coastal Plain

AbstractCereal rye is an effective winter cover crop because it accumulates residual soil N and reduces nitrate leaching. Wheat, barley, and triticale are alternative winter small grain species that may be managed as winter cover crops and yet produce marketable commodities. The objectives of this research were to evaluate N recovery capacity and grain yields of wheat, barley, triticale, and cereal rye grown as winter cover crops. Field plots established in 1996 and 1997 at two different locations on Maryland's mid-Atlantic Coastal Plain were amended with annual spring applications of four rates of broiler litter in a randomized complete block design with four replications. Each manure rate plot was divided into four subplots by planting four winter small grain cover crops: wheat, barley, triticale, and cereal rye. Rye cover crop treatments were killed with herbicide when the plants were 30 to 50 cm tall, while the wheat, barley, and triticale treatments continued to grow until grain maturity. Barley, rye, triticale, and wheat cover crops exhibited similar capacities to accumulate soil N, and therefore, reduce the potential for NO3—N leaching to groundwater. At the time of rye kill-down, aerial biomass N accumulation ranged from 11 to 112 kg N ha−1 and soil NO3—N levels were low (&lt;1.5 mg NO3—N kg−1) and relatively uniform across treatments. Average barley, triticale, and wheat grain yields increased with previous broiler litter application rate and initial soil NO3—N concentration. Potential income derived from the grain and straw produced could partially or completely offset cover crop production costs.

Early season nitrogen accumulation in winter wheat

Cereal rye (Secale cereale L.) is widely used as a winter cover crop to conserve soil residual nitrogen (N) in the mid‐Atlantic region of the United States. Cereal rye, however, has agronomic drawbacks that may make other winter small grain crops more desirable alternatives. Winter wheat (Triticum aestivum L.) is a small grain that could substitute for cereal rye as a cover crop because it would give growers the flexibility of using it as a cover crop or growing it to maturity. There is currently little information on early season N accumulation of winter wheat cultivars, which is critical for the success of a small grain cover crop. To determine the degree of variation in early season N accumulation and early season biomass yield in soft red winter wheat in the mid‐Atlantic region, twenty‐five commercially available cultivars were evaluated at Beltsville, MD in the 1996/1997 and 1997/1998 growing seasons. Acereal rye cultivar ("Wheeler") was included as a cover crop control. Samples of plant tissue were taken at Feekes growth stage 5 and at physiological maturity each year. There were significant differences among cultivars for early season N accumulation and biomass yield. A large group of wheat cultivars had similar early season N accumulation and biomass yield as the cereal rye cover crop control. This suggests that some cultivars of winter wheat may be as effective as cereal rye as a winter cover crop. Early season N accumulation was highly correlated (r=0.90***) with early season biomass yield rather than with plant N content. These results indicate that soft red winter wheat has potential as a dual grain and cover crop and could be considered an alternative to cereal rye as a winter cover crop for conserving residual soil nitrogen in the mid‐Atlantic region of the United States.

Reduction of Yield Components by Barley Yellow Dwarf Infection in Susceptible Winter Wheat and Winter Barley in Virginia

Five field studies, during 3 yr (1990-1993) and at two locations, were conducted in eastern Virginia to determine the effect of naturally occurring barley yellow dwarfvirus (BYDV) infection on yield components of susceptible 'Barsoy' winter barley (Hordeum vulgare L.) and susceptible 'Wakefield' winter wheat (Triticum aestivum L.) At each study site, yield components were compared for grain harvested from 25 disease loci and 25 adjacent asymptomatic areas. Rhopalosiphum padi L. and Sitobion avenae Fabr. aphid populations were monitored weekly by visual inspection of plant leaves and stems. Aphid numbers were low in all studies, with only one site exceeding the economic threshold of 15 aphids/row ft at any time during the season. The BYDV, PA strain, was present in all five studies ; the MAV strain was present at only one location in 1990-1991. Fall infection was predominant and occurred in all studies, with plants showing typical disease symptoms. Symptoms consistent with spring infection were observed in only one study. With few exceptions, fall infection significantly reduced tiller height, head number, seed number, number of seed per head, 1000 seed weight, and yield. Yield components were not equally affected. Seed number, number of seed per head and yield were reduced the most, by 28%, 22%, and 34%, respectively, compared with only about a 5 to 13% reduction in the other components. Spring infection significantly reduced number of seed per head and 1000 seed weight, but not the other yield components.

Seasonal Abundance of Thrips (Thysanoptera) on Winter Small Grains in Georgia

Thrips species composition and seasonal abundance were studied in winter wheat, Triticum aestivum L., and winter rye, Secale cereale L., during 3 seasons in the coastal plain region of Georgia. Thrips abundance also was examined in wild radish, Raphanus raphanistrum L., a common annual winter weed in small-grain fields. Limothrips cerealium (Haliday) and Frankliniella fusca (Hinds) were the 2 dominant species comprising >89% of the adult thrips collected in both crops. Frankliniella tritici (Fitch), F. bispinosa (Morgan), F. occidentalis (Pergande), F. williamsi Hood, Haplothrips graminis Hood and Plesiothrips perplexus (Beach) also were collected in low numbers in most years. Winter rye supported breeding populations of F. fusca during the autumn, winter, and early spring. Few thrips of any species were collected in winter wheat before spike emergence in March. However, large numbers of F. fusca and L. cerealium developed in wheat during the spring. Winter rye also served as a spring host for these thrips, but population increases were limited by grazing and early crop destruction. Differences in F. fusca phenology between wheat and rye probably are related to crop planting time in that rye for grazing is planted ≈6 wk earlier than wheat for grain production. Small grains grown for grain production presumably are planted too late for colonization by F. fusca in autumn. Although F. tritici , F. bispinosa , and F. occidentalis adults were present in the spring, these thrips probably did not breed extensively in wheat or rye. However, flowering wild radish in wheat fields supported large populations of F. tritici and F. occidentalis in late winter and spring. Therefore, winter small grains, particularly wheat, are important sources of F. fusca and L. cerealium that attack summer hosts. Small grains are not a major source of other Frankliniella spp., except possibly F. williamsi , but wild radish within winter small grains probably is an important spring source of F. tritici and F. occidentalis .

Simulated Insect Defoliation of Seedlings and Productivity of Winter Small-Grain Crops

Insects, such as grasshoppers, Spodoptera spp. armyworms and flea beetles, occasionally defoliate seedlings of autumn-planted small grain crops. Seedlings of wheat, Triticum aestivum L., barley, Hordeum vulgare L., oats, Avena sativa L., rye, Secale cereale L., and triticale, X Triticosecale Wittmack, were mechanically clipped at the soil surface to simulate insect leaf injury for various periods after planting up to the 1-, 2-, and 4-leaf stages. Defoliation up to the 4-leaf stage (i.e., ≥ 30 days after planting) delayed spike emergence of all crops by several days. Seedling defoliation generally had little adverse effect on grain yield and test weight of rye in any year and reduced yield of triticale in one of three years. Furthermore, plants of both species defoliated in the 2- and 4-leaf stages were less severely damaged by cold temperatures and yielded as much or more than nondefoliated plants when late freezes occurred. Seedling defoliation up to the 4-leaf stage also had little negative effect on grain yield and test weight of wheat. Grain yield of barley and oats declined with increasing length of defoliation period in two of three seasons with most of the reduction occurring when defoliation exceeded 20 days. Results imply that seedling defoliation up to the 4-leaf stage has little effect on grain yield and test weight of winter wheat, rye, and triticale. Defoliation only adversely affected yield of barley and oats when it occurred beyond the 2-leaf stage. As long as plant stand is not reduced, economic thresholds for seedling pests of winter small-grain crops that do not allow for the loss of most leaf tissue for several weeks after planting probably are too conservative.

Effect of Early and Late Flowering on Agronomic Traits of Soybean at Different Planting Dates1

Double‐cropping soybean [Glycine max (L.) Merr.] after a winter small grain crop often forces planting to be delayed beyond the date when maximum yield, plant height, and vegetative mass can be attained. The objective of this study was to evaluate soybean plant introduction (PI) lines selected for differing flowering dates, but with a constant maturity, for differences in vegetative size and yield reduction due to delayed planting. Two groups, each consisting of 12 PI lines, were compared in the field at Lexington, KY for 3 yr (1982–1984) in early (15 May) and late (21 June) planting on a Maury silt loam (fine, mixed, mesic Typic Paleudalf) soil. The early flowering group (group EF) flowered 10 days and matured 1 day earlier than the late flowering group (group LF). Group LF was taller with more nodes at Rl, R4, and R7 in both planting dates. The flowering and pod initiation (R1–R4) and seed filling (R4–R7) periods were shorter in group LF than in group EF. Yields averaged over all 3 yr were 1510, 1520, 1370, and 1380 kg ha−1 for group EF early planting, group LF early planting, group EF late planting, and group LF late planting, respectively. Both groups showed a 9% decrease in yield due to delayed planting. The planting date effect was highly significant, while the group effect and the planting date ✕ group interaction were nonsignificant for yield. In 1983 and 1984, group LF had smaller yield reductions in delayed plantings than group EF (6 and 17% reductions for each group, respectively). Although the planting date ✕ flowering group interaction for yield was highly significant in 1983 and 1984, group LF did not yield significantly more in late plantings. In 1982, the two groups did not differ in yield in late plantings. Thus, in this sample of soybean Pis, delayed flowering increased height and vegetative size but did not provide a yield benefit in late plantings.

Integrated Systems for Control and Management of Downy Brome (Bromus tectorum) in Cropland

Downy brome (Bromus tectorumL. # BROTE) may be a troublesome weed in winter small grains, perennial legumes, perennial grasses grown for seed, and orchards. In Nebraska, winter wheat (Triticum aestivumL.) yields have been depressed 30% by downy brome populations of 11 to 22 plants/m2(8). In Oregon, downy brome densities of 108 to 160 and 538 plants/m2reduced yields by 40 and 92%, respectively (22, 23). In Idaho, wheat yields were depressed 20 to 40% with 55 to 110 plants/m2(18). Downy brome has also been shown to lower yields and quality of hay from infested fields of alfalfa (Medicago sativaL.) (29). In perennial grass seed fields, downy brome may cause a serious seed quality problem (16). Some grass seed lots have contained as much as 50 to 75% downy brome seed.

Yields of Warm‐ and Cool‐Season Forages on Adjacent Soils1

AbstractKnowledge of average yields that can be expected over a period of years for a soil mapping unit helps in the use of soil survey information. Even the most recent soil surveys must rely on estimates from experiments and experience. For yields of principal crops these estimates are adjusted for the effects of soil‐water relationships and often must be extrapolated to similar soils for which no data are available. The objective of this study was to determine the yield on adjacent soils varying primarily in their moisture‐supplying capacity and natural drainage, of adapted perennial and annual warm and cool‐season forages and small grains grown under the same general climatic influence and management.The yields of 12 forage crops that grow mostly from spring to autumn were measured for 5 years on five adjacent soils with similar aspect. Later, eight winter small grain cultivars were grown for hay and grain for 3 and 4 years, respectively, on the same sites. The soils used belong to the Eutrochrepts, Hapludults, Paleudults, Fragiudults, and Ochraquults great groups.The soils were characterized in terms of their yield for each crop, ranging from 1,035 to 5,735 kg/ha for the warm‐season crops and from 2,225 to 6,760 kg/ha dry matter for the cool‐season forages. Since the many forage crops adapted to the landscape studied have different periods of growth and can satisfy different animal nutritional needs in different forage systems, no attempt was made to compare species within each soil studied. However, the data presented will help in soil selection for crops needed within specific forage systems on the landscape.

The Effects of Grazing Winter Small Grains1

Agronomy JournalVolume 39, Issue 8 p. 659-666 Article The Effects of Grazing Winter Small Grains1 John B. Washko, John B. Washko Formerlv Associate Agronomist. Tennessee Agricultural Experiment Station; now Associate Professor of Agronomy, Pennsylvania State College and Experiment Station State College, Pa.Search for more papers by this author John B. Washko, John B. Washko Formerlv Associate Agronomist. Tennessee Agricultural Experiment Station; now Associate Professor of Agronomy, Pennsylvania State College and Experiment Station State College, Pa.Search for more papers by this author First published: 01 August 1947 https://doi.org/10.2134/agronj1947.00021962003900080002xCitations: 6 1 Contribution from the Tennessee Agricultural Experiment Station, Knoxville. Tenn. Published with the approval of the Director. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume39, Issue8August 1947Pages 659-666 RelatedInformation