Lower Dry Matter Yield Research Articles

Dry matter yield and nitrogen recovery from bromegrass in south‐central Alberta as affected by rate of long‐term nitrogen applications

Abstract A field experiment was conducted on a Thin Black Chemozemic soil at Crossfield in south‐central Alberta to determine the effect of long‐term application of ammonium nitrate on dry matter yield (DMY), protein yield (PY), protein concentration, N use efficiency and recovery of N applied to bromegrass (Bromus inermis Leyss.) grown for hay. The N fertilizer was applied at 0, 56, 112, 168, 224, 280, and 336 kg N/ha in early spring of every year from 1968 to 1986. The DMY increased with applied N achieving a maximum at 224 kg N/ha, though the rate of increase in DMY from N fertilization was greatest with the first two increments applied (i.e. 56 and 112 kg N/ha). Protein yield and protein concentration maximized at 336 kg N/ha. The DMY was greater with a single‐cut system than with a double‐cut system. The DMY varied from year to year, but it was not closely related to precipitation received during the April to August period (R2 = 0.37). However, in some years low DMYs were associated with low precipit...

The effect of time of sowing and sowing method on production of white clover in mixed swards

Two field trials were carried out in successive years in which (1) perennial ryegrass and white clover seeds were drilled together, or (2) clover was broadcast and grass drilled, or (3) both clover and grass were broadcast. The last two treatments were followed by harrowing or not of the seed bed. Sowing took place in early May or August. Four harvests were taken in each full harvest year. In establishment years, sowing in May resulted in a total dry matter (DM) production at least ten times higher than that resulting from sowing in August. No sowing method treatment effects on total DM or clover yield were significant in the establishment year (measured only in spring-sown plots). In the first harvest year the August-sown treatments produced 15% less DM than those sown in May and clover yield was, on average, 40% lower than the earlier sown treatments; clover proportion followed a similar pattern to yield. Drilling of both grass and clover without harrowing produced swards with a significantly lower proportion of clover in the first harvest year in the first trial than in treatments in which clover was broadcast but not harrowed. In the second trial at harvest 1, clover proportion just failed to be significantly lower in the treatment in which grass and clover were drilled than in the treatment when clover was broadcast and the seed bed harrowed. In the second harvest year (first trial only), annual clover yield and proportion were not affected but drilled grass and clover had lower DM yield than when grass was drilled and clover broadcast without harrowing and when both were broadcast, without harrowing. At one harvest, the yield of clover in treatments sown in May was actually lower than that in the later-sown plots. In a subsidiary controlled environment experiment to investigate the effect of stage of clover development on cold hardiness (a factor in autumn-sown swards), plants which were about to initiate stolons (58 days old) had an LD50 of −5·1° compared with −9·3°C for plants 60 days older. It is concluded that autumn sowing delays the time at which optimum clover production is achieved (late in the first full harvest year) and method of sowing does not compensate for this. However, sowing in August under Northern Ireland conditions does not seem to jeopardize the chances of a successful establishment of white clover, and plants should be sufficiently winter hardy to withstand relatively hard freezing conditions.

No‐Till Winter Wheat Dry Matter and Tissue Nitrogen Response to Nitrogen Fertilizer Form and Placement

AbstractExpansion of winter wheat (Triticum aestivum L.) production into the high winterkill risk regions of the Canadian prairies has been achieved by no‐till seeding into standing stubble immediately after harvest of the previous crop. Seven field trials were conducted in Saskatchewan to evaluate the seasonal pattern of dry matter and N accumulation of no‐till winter wheat. The fertilizer treatments included the currently recommended early (20 April) spring broadcast ammonium nitrate (AN) and early spring broadcast and surface band applied urea and urea‐ammonium nitrate (UAN) solution. In four of the seven trials, late (12 May) AN and urea were also applied. Nitrogen fertilizer was applied at 0, 34, 67, 101, and 202 kg N ha−1. Mean maximum dry matter and N yields were established by Zadoks Growth Stage 65 (ZGS65) and ZGS45, respectively. Subsequent losses of both dry matter and N were observed under conditions of high evaporative demand and low precipitation. When rainfall was more favorable and N supply abundant, N and dry matter yields increased through the growing season to harvest. Increased N rates increased N uptake and amplified plant‐N and dry matter losses. Growing season environmental conditions and plant‐available‐N levels also played an important role in determining the efficiency of N translocation to the seed. Early broadcast AN produced larger dry matter and N‐yield responses than all other fertilizer treatments. While surface band applied urea showed no advantage over early broadcast urea, surface band applied UAN increased dry matter yield and N uptake over broadcast sprayed UAN. Average dry matter (N) yield‐N response for early broadcast urea, surface band applied urea and surface band applied UAN treatments were 93 (89%) of those recorded for early broadcast AN. The broadcast sprayed UAN treatment dry matter and N yield‐N responses were 81% of early broadcast AN. Compared with early broadcast AN and urea, late broadcast AN and urea produced lower dry matter yields and delayed N uptake. Average late broadcast AN and urea dry matter (N) yield‐N responses were 63 (85%) of those recorded for early broadcast AN and urea. These observations indicate that differences in dry matter and N‐yield responses for different N forms and placement methods are established early in the growing season and maintained through to maturity.

Effect of fertilizer nitrogen rate and timing on herbage production and nitrogen use efficiency for first‐cut silage

AbstractEight field‐plot experiments were carried out on established grassland swards between 1984 and 1988 to examine the effects of date and rate of application of calcium ammonium nitrate (CAN) on herbage dry matter (DM) yield and apparent efficiency of nitrogen (N) use at first‐cut silage.CAN application significantly increased (P <0 ·001) the mean yields of herbage and N uptakes by herbage in all experiments. Herbage yields were similar (P > 0·05) with N rates of 100 kg ha−1, 125 kg ha−1 or 150 kg ha−1 in five experiments but in the other three there were increases above 100 kg ha−1. Date of N application had a significant effect on DM yield in three experiments; this effect was inconsistent for both single and split dressings. Lower production was associated with reduced uptake of N, a trend that primarily reflected lower DM yields and not wide herbage N content variation.It is concluded that selection of the date on which to apply fertilizer N in early spring to obtain optimum herbage yields at first‐cut silage often required little precision. The use of fertilizer N rates >100 kg ha−1 should be questioned where there are likely to be appreciable quantities of available N derived from non‐fertilizer sources.

Nitrogen leaching and uptake from calcium cyanamide in comparison to urea and calcium ammonium nitrate in an ultisol from the humid tropics

Leaching loss of N applied as calcium cyanamide (CaCN2 — 19% N), urea and calcium ammonium nitrate (CAN — 26% N) to a coarse textured, kaolinitic ultisol profile was studied in the laboratory using undisturbed soil columns. The soil columns were leached with an amount of water equivalent to the annual rainfall of the sampling site (2420mm) using a rainfall simulator over a period of 42 days. The ‘leachability’ of the three N fertilizers differed greatly and followed the order of CAN > urea > CaCN2. Most of the N lost through leaching was in NO3 form. Calcium cyanamide lost only 3% of applied N. Breakdown of CaCN2 to NH4 was incomplete (64%) and nitrification in the soil was inhibited resulting in negligible leaching loss. Nitrogen retained in the soil columns after the leaching cycle was mainly in ammoniacal form irrespective of source of N used. Effectiveness of CaCN2 as a N source was also studied in a greenhouse experiment with maize (Zea mays) and upland rice (Oryza sativa) as testing crops. Calcium cyanamide applied one week before sowing of crops was as effective as CAN and urea under conditions of no N leaching. When applied at the time of planting and two or more weeks before planting gave lower dry matter yields and N uptake than CAN and urea.

Dryland Grain Sorghum Water Use, Light Interception, and Growth Responses to Planting Geometry1

AbstractCrop yields are primarily water‐limited under dryland production systems in semiarid regions. This study was conducted to determine whether the growing season water balance could be manipulated through planting geometry. The effects of row spacing, row direction, and plant population on the water use, light interception, and growth of grain sorghum [Sorghum bicolor (L.) Moench] were investigated at Bushland, TX, on a Pullman clay loam (fine, mixed, tbermic Torrertic Paleustoll). In 1983, which had a dry growing season, narrow row spacing and higher population increased seasonal evapotranspiration(ET) by 7 and 9%, respectively, and shifted the partitioning of ET to the vegetative period. Medium population crops yielded 6.2 and 2.3 Mg/ha of dry matter and grain, respectively. High population resulted in high dry matter (6.1 Mg/ha) and low grain yield (1.6 Mg/ha), whereas low population resulted in low dry matter (5.4 Mg/ha) and high grain yield (2.3 Mg/ha). Row direction did not affect water use or yield. In 1984, dry matter production for a given amount of ET and light interception was higher in the narrow‐row crops. Evapotranspiration was less for a given amount of light interception in the narrow‐row crops and in the north‐south row crops. Narrow‐row planting geometry appears to increase the partitioning of ET to the transpiration component and may improve the efficiency of dryland cropping systems.

Analysis of Primary Spring Growth of Four Pasture Legume Species1

AbstractAlfalfa (Medicago sativa L.) is the most‐used forage legume in the northern USA; however, it has several shortcomings, especially as a pasture species. Among northern‐adapted forage legume species that are potential alternatives in grazing situations are birdsfoot trefoil (Lotus corniculatus L.) sainfoin (Onobrychis viciifolia Scop.), and cicer milkvetch (Astragalus cicer L.). We conducted an analysis of primary spring growth of these four legumes to determine patterns of dry matter, crude protein (CP), and in vitro digestible dry matter (IVDDM) accumulation. The legumes were established on a Waukegan silt loam (Typic Hapludoll) in late July 1981. Beginning on 10 May 1982 and 1983, total forage was harvested weekly until 28 June when total forage accumulation had decreased. Near infrared reflectance spectroscopy was used to determine CP and IVDDM for leaves, stems, and reproductive parts for each species. All four species reached maximum dry matter accumulation on 21 June. Sainfoin produced the greatest forage dry matter (8.51 Mg ha−1); however, it also had the lowest IVDDM and CP concentration on 21 June. Thus, sainfoin had IVDDM and CP accumulations similar to those of other species. Cicer milkvetch had the greatest IVDDM concentration (67.6 dag kg−1) on 21 June, but its relatively low forage dry matter yield during primary spring growth reduced its IVDDM accumulation to an amount similar to that of the other species. Alfalfa had the greatest CP concentration on 21 June, but its CP yield exceeded only that of cicer milkvetch. None of the four species was definitely superior under these growth conditions. However, birdsfoot trefoil, sainfoin, and cicer milkvetch all showed potential as pasture substitutes for alfalfa, especially in that they did not reach a leaf‐to‐stem ratio of 1.0 or less until considerably later than alfalfa.

Effect of certain ions on growth and uptake of iron and zinc by barley seedlings grown on alluvial soil

Abstract Pot experiments were conducted to study the effect of different types and concentrations of Na and Ca salts separately or in combination with either FeSO4 or ZnSO4 on the growth and Fe and Zn uptake by barley (Hordeum vulgare L.) seedlings grown on art alluvial soil. Dry matter yields of plants increased when the different treatments were applied. Highest dry matter yields were obtained by the addition of CaCl2, while the lowest dry matter yields were obtained by the addition of Na2SO4.. Moreover, Fe uptake by barley seedlings increased by the addition of mono‐ or divalent ions to the soil. The favorable effects of mono‐ or divalent ions were nearly double with FeSO4 treatments. The application of ZnSO4 to the soil depressed the uptake of Fe by plants. The application of mono‐ or divalent ions enhanced Zn uptake by plants. Zinc uptake increased with applications of ZnSO4, but decreased with applications of FeSO4.

Weed management in opium poppyPapaver somniferumL.

Abstract Field trials were carried out during winter seasons of 1981–82 and 1982–83 to assess the efficacy of the herbicide chlortoluron and hand weeding in controlling weeds in opium poppy at the Rajasthan College of Agriculture, Udaipur. Application of Chlortoluron at 1.5 kg/ha resulted in high yield of opium latex and seed and low weed count and weed dry matter yield at harvest, compared with the effect of hand weedings after 20, 40 and 60 days.

ECOLOGICAL ADAPTATION IN Lolium perenne L.: PHYSIOLOGICAL RELATIONSHIPS AMONG PERSISTENCE, CARBOHYDRATE RESERVES AND WATER AVAILABILITY

Cultivars of Lolium perenne L. when removed from their area of adaptation, especially in the latitudinal sense, are usually less persistent than adapted varieties and disappear after a few years. This phenomenon is particularly remarkable for North European varieties when cultivated in Mediterranean regions which are characterized by a period of drought stress (from the 2nd week of June to 2nd week of August). Two varieties of Lolium perenne L., Vejo (adapted to Central Italy) and Lenta (North European cultivar), were sown in September 1979 and compared to evaluate the effects of water stress on persistence from June 1980 to January 1982 at Perugia, central Italy. Measurements recorded included ground cover, plant survival, dry matter yield (DMY), number of tillers per plant, and water soluble carbohydrate (WSC) content. Trials were performed, according to a split-plot design with three replicates, in dense stands (seeding rate of 2000 viable seeds/m2) and in spaced plants (40 × 60 cm apart) which were either irrigated or nonirrigated. The results show that Vejo, starting from the 2nd year from sowing, had higher values than Lenta for ground cover, plant survival and number of tillers per plant. The same behavior was observed for DMY with the exception of the August 1981 sampling in which the situation was reversed because of the summer dormancy of the local variety. The pattern of WSC content also differed between the two cultivars with the adapted type characterized by higher values than the unadapted one except in winter. Irrigation during the dry season increased DMY by preventing dormancy of the local cultivar and by stimulating vegetative activity of the unadapted one, but neither influenced the mortality of the foreign cultivar or the WSC content in either variety. These results suggest that the low DMY produced in summer by the unadapted cultivar is obtained at the expense of carbohydrate reserves. The reduction of WSC (mg∙plant−1) in Lenta from May to August was 43% in dry and 47% in irrigated conditions versus 22% and 32%, respectively, in Vejo. Severe depletion of reserves seems to be the main cause of the thinning of the unadapted variety (the ground cover evaluated in October 1981 was 18% and 22% in Lenta and 82% and 93% in Vejo in nonirrigated and irrigated conditions, respectively). For these reasons the lack of persistence of the unadapted cultivars of perennial ryegrass in Mediterranean regions cannot be attributed to the extent of summer water shortage characterizing these areas.Key words: Lolium perenne L., environmental adaptation, persistence, carbohydrate reserves, stress in Mediterranean areas

Sorghum genotype differences in phosphorus uptake rate and distribution in plant parts

Abstract Relatively low amounts of the phosphorus (P) added to soils is recovered by plants. Many plants show differences in their ability to take up and use P, but the mechanisms for these differences are not fully understood. The purpose of this study was to determine differences among sorghum [Sorghum bicolor (L.) Moench] genotypes for P uptake rates and distribution in plant parts. Differences in P uptake rates were determined for six sorghum genotypes at 24, 38, and 52 days of age at three P levels. Larger differences were noted among genotypes in 24‐day‐old plants than for older plants. Uptake rates were 6‐ to 14‐times higher (dependent on genotype) in 24‐day‐old plants than in 52‐day‐old plants. NB9040 which had the highest dry matter yield at each age had the lowest rate of P uptake, and CK60‐Korgi which had the lowest dry matter yield at each age had the highest rate of P uptake. Only small differences were noted among genotypes for distribution of P within plant parts for younger plants. Older p...

Tiller dynamics and growth of Rhodes grass after defoliation: A model named TILDYN

The dynamics in tiller population and dry-matter accumulation of a grass sward, cut at different time intervals, was compared with a descriptive simulation model. The model was validated against experimental data of tiller number, and dry-matter accumulation for irrigated cv. Katambora Rhodes grass ( Chloris gayana Kunth), cut at intervals of 1, 2, 3 or 4 weeks. The model predicted that the initial rate of regrowth following long cutting intervals was much slower than the regrowth following short cutting intervals. The simulations also showed that relatively high dry-matter yields alternated with relatively low dry-matter yields when the interval between cuttings was long. These results were in reasonable agreement with the measured values. The fluctuation in the number of tillers and dry-matter yield was attributed mainly to the formation of culmed-vegetative tillers, common to Rhodes grass at an early stage of development, which renders them incapable of regrowth after defoliation.

Effects of Flower Bud Removal and Nitrogen Supply on Growth and Development of Cotton (Gossypium hirsutum L.)

Effects of flower bud removal for various durations (20 or 90 days following first flower bud appearance or 35 days following first flower opening) and nitrogen supply (non-limiting and 33 % of the nitrogen uptake of non-limited plants) on growth characteristics of glasshouse-grown cotton plants are reported. Removal of flower buds and high nitrogen supply stimulated elongation of the main stem and the number of fruiting positions per plant. Nitrogen supply increased both main stem node number and mean internode length whereas flower bud removal increased only the number of nodes on the main stem. Flower bud removal did not reduce total dry matter yields, number of flowers produced or number of bolls. Vegetative organs provided efficient storage for excess assimilates resulting from the complete suppression of fruiting activity. Plants subjected to nitrogen stress had lower dry matter yield, number of flowers and number of bolls. Compensation following flower bud removal was greater at higher than at lower nitrogen supply. Relative fruitfulness, the partition of biomass between vegetative and reproductive organs, was not affected by either flower bud removal or nitrogen supply.

In Vivo Quality of Tall Fescue as Influenced by Season, Legumes, Age, and Canopy Strata1

AbstractFall‐grown tall fescue (Festuca arundinacea, Schreb.) provides a relatively inexpensive forage for winter grazing. Quality and yield of actively growing tall fescue increases when accumulated from August and harvested through time in the early fall. The effect of regrowth age on fall accumulated tall fescue quality has not been evaluated under similar harvest climates and animal performance on summer grown tall fescue is often low. Therefore a series of experiments were conducted to evaluate the in vivo quality of tall fescue in summer, alone and in combination with a legume, and to evaluate the in vivo quality of tall fescue of different regrowth ages harvested in December.Summer grown tall fescue, alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were fed alone and compared with 50:50 mixes of each legume with tall fescue. Orchardgrass (Dactylis glomerata L.) was also fed alone and with red clover during 1 year. Low in vivo digestible dry matter (DDM) of 35.8% for tall fescue 60 days old in 1975 was associated with droughtimposed dormancy. Nondormant, 40‐day‐old alfalfa regrowth was highly digestible (59.4% DDM). In 1976, the digestibilities of tall fescue and red clover were similar (54.8 and 53.9% DDM) and lower than that of orchardgrass (57.0% DDM). Consistent, nonsignificant trends in increased digestibility occurred with the inclusion of a legume which were sufficiently large to have potential economic consequences on animal production.In another experiment, tall fescue was accumulated from mid‐June, July, August, and September, with 112 kg N/ha applied in mid‐August, to evaluate the influence of age on in vivo quality when fed to sheep in early December. Quality decreased with increasing age. In 1975, June accumulated forage was significantly lower in quality than forage with shorter accumulation periods. In 1976, quality decreased with increased ages of the accumulated growth, ranging from 51.0 to 60.5% DDM for June and August accumulated forage, respectively. Quality of September accumulated forage was low (52.8% DDM), apparently due to high lignin and insoluble ash contents. Improved quality with shorter accumulation periods was offset by lower dry matter yields (5.2 vs. 2.2 metric tons/ha) and DDM yields were also reduced (1.7 vs. 1.2 metric tons/ha) from June to September, respectively. Accumulating tall fescue from as early as mid July did not decrease digestibility or intake sufficiently to make this practice impractical for winter grazing. Summer utilized tall fescue was lower in quality than that utilized in winter. There were significant correlations between DDM and TNC contents.

SELECTION FOR DRY MATTER YIELD IN LOLIUM PERENNE L. I. DIRECT RESPONSE TO SELECTION

Selection for high and low dry matter yield within an ecotype of Lolium perenne L. was effective in producing two highly differentiated populations. The evaluation of the materials obtained after three cycles of selection snowed a realized heritability of 0.13 and a symmetrical response in the two directions of selection. The difference between populations selected in opposite directions was 448.9 mg/plant and was significant from early stages of development. After four cycles of selection, realized heritability was 0.10. The low heritability estimate suggested that more efficient selection criteria for the improvement of forage yield are needed.

SELECTION FOR DRY MATTER YIELD IN LOLIUM PERENNE L. II. CORRELATED RESPONSES UNDER TWO CUTTING REGIMES

The correlated responses to divergent selection for dry matter yield within an ecotype of Lolium perenne L. were evaluated in two experiments under different cutting regimes. Both experiments showed that selection for dry matter yield did not affect leaf size and caused asymmetrical correlated responses on the rate of tiller production and the rate of leaf appearance. Selection for high dry matter yield resulted in an increased rate of tiller production without change in the rate of leaf appearance. Selection for low dry matter yield did reduce both the rate of leaf appearance and the rate of tiller production.

Effect of spring tillage on seedbed characteristics, plant establishment and yield of silage corn on a light sandy soil

On light sandy soils in the eastern and southern part of The Netherlands late spring ploughing has become a wide-spread practice for growing silage corn on dairy farms with arable acreage. No consensus exists about the desirability of a loose or more compacted seedbed with respect to seedling establishment and final yield when planting is followed by unstable weather. In a field experiment, three types of seedbed were obtained by (1) early spring ploughing with natural settling of the tilled layer (‘moderately compact’); (2) late spring ploughing (‘loose’) and (3) late spring ploughing with surface compaction added (‘compact’). Depth of planting, as affected by bulk density of the seedbed, and delayed seedling emergence, as affected by a cool, wet period, both influenced the final plant population. Though early growth of seedlings was better on a loose seedbed, no significant differences in final dry matter yield between the three tillage practices could be found. In a side study, plant rows were compacted after planting, resulting in a reduced plant number and a lower dry matter yield. Suggestions are given for further research to obtain more information with respect to tillage practices and seedbed conditions required for successful growing of silage corn on light sandy soils.

Nitrogen and phosphorus nutrition of dryland grain sorghum at Katherine, Northern Territory. 2. Effect of rate and source of phosphorus fertilizer

Field experiments were conducted at Katherine, Northern Territory, in 1970-71 and 1971 -72 to examine responses of dryland grain sorghum to applied phosphorus at different growth stages. In the first, the effect of rate of application up to 100 kg P ha-1 as triple superphosphate was investigated. Growth responses to phosphorus were noted from mid-elongation onwards, but the magnitude of response varied between seasons, being greater in the higher rainfall season 1970-71. Maximum yields of grain were 7730 kg ha-1 with 50 kg P ha-1 in 1970-71, and 4440 kg ha-1 with 100 kg P ha-1 in 1971-72, which were increases of 49 and 37 per cent respectively over the appropriate zero phosphorus treatment. These suggested an increased requirement for phosphorus over previous recommendations. Phosphorus reduced the time from emergence to anthesis from 68 to 60 and from 70 to 63 days respectively in the two seasons. About half of the plant phosphorus was taken up after anthesis. It was concluded from soil analysis that phosphate-treated plots had an enhanced supply of phosphorus throughout the period of crop growth. In the second study, four phosphorus sources (superphosphate, triple superphosphate, monoammonium phosphate, and diammonium phosphate) were compared. With 25 kg P ha-1 and with constant nitrogen, grain yield response followed the order superphosphate > monoammonium phosphate > diammonium phosphate > triple superphosphate in both years. Triple superphosphate tended to give lower dry matter yields and nitrogen and phosphorus concentrations than the other three sources.

Effect of pH and phosphate on soluble soil aluminium and on growth and composition of kikuyu grass

Kikuyu (Pennisetum clandestinium Hochst) grew relatively poorly on the Wollongbar krasnozem at soil pH values below 4.36. At these low pH values dry matter yields were increased by raising the pH or by application of high rates of phosphate. Both treatments decreased the concentration of soluble soil-Al on which the concentration of Al in tops was linearly dependent (r=0.95).

Efficiency of utilization of nitrogen fertilizers on representative soils from southern New South Wales

The effects were examined in a glasshouse study of three forms of nitrogen fertilizer (urea, ammonium sulphate and sodium nitrate) on the yield, and nitrogen and phosphorus uptake of ryegrass (Lolium perenne) in six representative farming soils from the southern slopes and plains of New South Wales. The results indicated an average recovery of 82 per cent of applied nitrogen across the three forms of fertilizer and the six soils. Ammonium sulphate led to decreases in soil reaction of the order of 0.8-1.5 pH units and lower recoveries; sodium nitrate increased pH. Ammonium sulphate as a source of nitrogen is considered undesirable as it gave lower dry matter yields and nitrogen recovery values compared with the other fertilizer forms. In addition, because of its effect on soil reaction, it could lead to the loss of nutrients by leaching or fixation processes.