Response of bermudagrass selections from the Appalachian region to N and P fertilization

Abstract

A greenhouse experiment was conducted to evaluate the influence of N and P fertilization on the yield and forage quality of six cold tolerant bermudagrass (Cynodon dactylon L.) selections from the Appalachian region. Midland bermudagrass and limpograss (Hermarthria altissima) were included for comparison purposes. Each grass was treated with a factorial combination of three N rates (112, 224, and 448 kg N.ha^‐1) and four P rates (0, 25, 75, and 225 kg P.ha^‐1) Two bermudagrass selections from the Appalachian region demonstrated greater dry matter production than Midland bermudagrass. Yields of Quicksand common exceeded those of Midland by 60% to 236% over the range of treatments. High yielding selections were not inferior to low yielding selections when mineral concentrations, neutral detergent fiber, acid detergent fiber and acid detergent lignin levels were considered. The results of this investigation suggest that Quicksand common and Selection 13 merit further study to determine their potential for summer forage production in the Appalachian region.     

Influence of dolomitic limestone and N:P:K: Fertilization on the mineral composition of coastal bermudagrass grown under very acid soil conditions

Abstract

The influence of limestone and N:P:K fertilizer rates on elemental composition of Coastal bermudagrass forage was determined to evaluate causes for high yield responses to dolomitic limestone at high N:P:K rates, as well as severe stand loss, and chlorosis of bermudagrass in the unlimed treatments. Increasing N:P:K fertilization resulted in severe Mg deficiency. Maximum yields (when limed with dolomitic limestone) were associated with Mg concentrations of 1.0 g/kg plant tops. Magnesium lost to plant removal, Mg loss to enhanced leaching under N fertilization, and K interference associated with excess K accumulation at high rates of NK inputs all contributed to Mg deficiency. However, the accumulation of excess K, which interfered with Mg uptake when high rates of N and K were applied, was considered to be the primary cause of the observed Mg deficiency.     

Stand recovery of coastal bermudagrass following stand loss induced by potassium deficiency

Abstract

‘Coastal’ bermudagrass (Cynodon dactylon L. Pers.) stand loss resulting from K deficiency has been reported. The recovery of this perennial grass from K deficiency could very well take a significant time after the deficiency is corrected. Experiments were conducted on two soils, Darco (Grossarenic Paleudult; loamy, siliceous, thermic) and Cuthbert (Typic Hapludult; clayey, mixed, thermic). Previous P and K factorial rate studies had been conducted on the experimental sites. Annual K and P fertility rates used on prior studies were 0, 112, and 224 kg/ha K and 0 to 136 kg/ha P. These earlier treatments were overlaid with rates of 112 and 224 kg/ha of P and K, respectively. Data were taken for yield, stem length, stem weight, and rhizome production. Yield was found to be related directly to stand. Yield was also related to plant height under severe stand loss. Yield loss was not related to stem weight. Rhizome production recovered after two years. Yield had recovered by the end of the first year.     

不同钾水平对温室番茄生长、产量和品质的影响

采用营养液砂培试验技术,研究开花期一次施用不同钾水平营养液处理对番茄生长、产量和品质的影响.结果表明:在番茄植株拉秧时,高浓度钾水平T1 (K+:9 mmol/L)和T2(K+:12 mmol/L)茎粗显著大于对照(K+:6 mmol/L),分别比对照增加10.03％和9.08％;在处理后第8d,T2比T1和对照的净光合速率分别增加4.58％和12.96％,且差异显著;T1单株产量最高,比对照增加4.65％;T1和T2果实Vc的含量较对照分别显著增加15.25％和14.46％,T2显著降低了果实中硝酸盐含量,T1显著增加了果实中可溶性固形物含量,T1和T2糖酸比分别比对照高9.67％和10.70％.     

Enzyme activities in hill land soils of the Appalachian region

Abstract

The top two horizons of 14 major hill land soils of the Appalachian Region were evaluated for activities of add phospha‐tase (AP), pyrophosphatase (PP1), arylsuifatase (AS) and urease (UR) enzymes. A relationship between enzyme activities and soil properties was examined. Surface horizons contained higher enzyme activities than the subsurface horizons. Overall, enzyme activities were positively correlated with soil moisture content, percent water‐filled porosity, C, N, K, Mn and CEC. Activities of AP and PP1 were negatively correlated with soil pH. The AP and UR activities were positively related to various forms of P. Enzyme activities were positively related to total and organic S. Pot trial was performed 1n green house conditions to evaluate the relationship between enzyme activities and snapbean (Phaseolus vulgaris L.) growth and N, P, and S uptake. With a few exceptions, activities of AP, AS and UR were positively related to snapbean shoot wt. and shoot content of N, P, and S. The PP1 activities of subsurface horizons were positively related to shoot wt. and mineral content. Enzyme activities varied from one soil horizon to another. The effects of various soil properties and their interacting factors on activities of the four enzyme systems are discussed.     

Effects of potassium supply on growth and yield of safflower as compared to sunflower§

Safflower may have a certain production potential under German conditions, particularly in organic farming where the putatively low nutrient requirement is highly welcomed. However, current knowledge regarding the nutrient requirements of safflower as compared to similar oil crops is limited. It was thus the aim of this study to determine the growth and yield response of safflower (Carthamus tinctorius L.) as compared to sunflower (Helianthus annuus L.) with respect to potassium (K) supply. Three safflower and two sunflower plants were cultivated in 5 L Mitscherlich pots. Both species responded strongly to increasing K supply with respect to plant growth and yield. Growth and yield of safflower increased up to 1 g K per pot, while the optimum for sunflower was 3.0 g K per pot. Safflower out‐yielded sunflower at low K supply, while at high K level, the opposite was observed. Supply of K affected virtually all yield components in both species, though to different degree. The number of capitula in safflower was only slightly affected, and the number of achenes per capitulum was only reduced under severe K deficiency, while single‐achene mass increased with increasing K supply. In sunflower, the number of achenes per capitulum strongly responded to the K supply, as did the single‐achene mass. Oil yield in safflower was affected by K deficiency mainly due to reduced achene yield, not oil concentration. However, oil yield in sunflower was severely affected by low K supply due to both reduced achene yield and lowered oil concentration. Multiple‐regression analyses indicate that in sunflower, the stem dry matter (DM) and the total amount of K accumulated in the aboveground biomass were most important, while in safflower the total amount of K and N accumulated had the highest impact. It is concluded that sunflower is more sensitive to inadequate K supply than safflower.     

EFFECT OF NITROGEN SOURCES AND RATES ON YIELD AND QUALITY OF SILAGE CORN

The objective of this study was to determine the effect of nitrogen (N) application source and rate on silage corn (Zea mays L.). Urea, ammonium nitrate, and ammonium sulfate were compared at 50, 100, 150, and 200 kg N ha^?1. The application of ammonium sulfate produced the highest plant height, leaf area index (LAI), total yield, and stem, leaf, and ear dry matter, followed by ammonium nitrate and urea. However, nitrogen sources had no marked effects on the content of protein, ash, oil, soluble carbohydrates, acid detergent fiber (ADF) and neutral detergent fiber (NDF). As the rate of nitrogen increased plant height, LAI, total yield, and stem, leaf, tassel, and ear dry matters, and protein, ash and oil contents increased while soluble carbohydrates, ADF, and NDF contents decreased. Ammonium sulfate was the most effective N source on production and 200 kg N ha^?1 was the most effective N rate on corn yield and quality.     

Plant density,distribution, and fertilizer effects on yield and quality of irrigated corn silage

Abstract

Grain deficits frequently occur in the Southeastern Atlantic Coastal Plain because erratic rainfall patterns and soil properties often limit corn (Zea mays L.) yields, however, harvesting corn for silage may enable farmers to produce a second grain crop during the same calendar year. Effects of row spacing, plant population, and fertilizer program on yield, quality, and mineral concentrations of corn silage grown with irrigation on Typic Paleudult soils were therefore investigated. Two plant population treatments which averaged 7.0 and 10.1 plants m^‐2 were evaluated with two fertilizer programs that differed in N, N and K, and N, P, and K in 1980, 1981, and 1982, respectively. Each plant density by fertilizer combination was evaluated in single rows spaced 96 cm apart and in twin rows which approximately doubled the intrarow plant spacing. Plot size for the 2×2×2 factorial experiment ranged from 30 to 44 m². Yield, quality, and mineral concentrations of corn silage grown in single rows spaced 96 or 75 cm apart and twin rows were also evaluated in large (185 m²) plots under center pivot irrigation during 1981 and 1982.

Dry matter yields of 22 to 26 Mg ha^‐1 were achieved with plant densities of 6.7 to 13.5 plants m^‐2 at both experimental sites. Highest silage yields were produced with stand densities of 9 m or more planted in single 75 cm or twin rows, but yield differences were statistically significant at P(0.05) in only two of five site years. Increasing total N‐P‐K application beyond 200–30–167 kg ha”; increased crude protein slightly in 1980 and significantly in 1981 and 1982. Concentrations of Mn and Zn in silage were increased by higher fertilization, presumably because nitrification reduced surface soil pH and increased their availability. Dry matter yield, fiber, energy, and other mineral nutrients were not significantly influenced by fertilizer program. These experiments identified management practices for the Atlantic Coastal Plain which resulted in corn silage yields equal to those produced in the cooler mountain region of Georgia and that exceeded current average production in South Carolina by approximately 40% without reducing apparent feed quality.     

营养液浓度对水培生菜生长和硝酸盐积累的影响

该文研究了4种营养液浓度处理(山崎生菜配方的1/4(1/4s)、1/2(1/2s)、1(1s)和2(2s)单位)对水培生菜(品种为“弘农”和“绿领”)生长、硝酸盐积累和品质的影响。结果表明，1/2单位营养液浓度处理下生菜地上部和根的鲜重、叶长和叶宽最大，而2个单位营养液浓度处理下上述指标最小。不同营养液浓度处理下叶片硝酸盐积累的高低顺序为2s>1s>1/2s>1/4s，2个单位营养液浓度处理下生菜生长发育后期叶片中的SOD活性和MDA含量最高。对采收时生菜品质的分析表明，生菜体内的硝酸盐含量随着营养液浓度的增加而迅速上升，2个单位营养液浓度处理下生菜叶片中硝酸盐、可溶性糖和可溶性蛋白质R 含量最高。综合考虑产量和品质，采用1/2单位的山崎生菜配方是适合生菜水培的营养液配方。     

营养液浓度对水培生菜生长和硝酸盐积累的影响

该文研究了4种营养液浓度处理(山崎生菜配方的1/4(1/4s)、1/2(1/2s)、1(1s)和2(2s)单位)对水培生菜(品种为“弘农”和“绿领”)生长、硝酸盐积累和品质的影响。结果表明,1/2单位营养液浓度处理下生菜地上部和根的鲜重、叶长和叶宽最大,而2个单位营养液浓度处理下上述指标最小。不同营养液浓度处理下叶片硝酸盐积累的高低顺序为2s>1s>1/2s>1/4s,2个单位营养液浓度处理下生菜生长发育后期叶片中的SOD活性和M DA含量最高。对采收时生菜品质的分析表明,生菜体内的硝酸盐含量随着营养液浓度的增加而迅速上升,2个单位营养液浓度处理下生菜叶片中硝酸盐、可溶性糖和可溶性蛋白质R含量最高。综合考虑产量和品质,采用1/2单位的山崎生菜配方是适合生菜水培的营养液配方。     

Effects of exogenous SA supplied with different approaches on growth,chlorophyll content and antioxidant enzymes of peanut growing on calcareous soil

To assess the role of salicylic acid (SA) supplied with 5 approaches in alleviating chlorosis induced by iron (Fe) deficiency in peanut plants growing on calcareous soil, SA was supplied as soil incorporation, making slow-release particles, seed soaking, irrigation and foliar application. SA application, particularly, SA supplied by slow release particles, dramatically increased growth parameters, yield and quality of peanut, and increased Fe concentration in peanut grain. Meanwhile, SA application increased the H⁺-ATPase activity, reduced pH of soil, increased Fe³⁺-Chelate Reductase (FCR) activity in roots, and increased Fe concentration in roots. Furthermore, SA increased active Fe content and increased chlorophyll content. In addition, SA improved enzymes activities containing superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and protected Fe deficiency induced oxidative stress. Therefore, SA has a good effect on alleviating chlorosis induced by Fe deficiency on calcareous soil. However, in the 5 SA supplied approaches, foliar application and making slow release particles were more effective.     

Performance of Kura clover compared to that of perennial forage legumes traditionally cultivated in central Europe

Kura clover (Trifolium ambiguum M. Bieb.) is a rhizomatous perennial legume that is native to Caucasia, is extremely persistent in North America, but its performance has not been adequately evaluated in Europe. The objective of this research was to compare forage yield and nutritive value of Kura clover to lucerne (Medicago sativa L.), red clover (Trifolium pretense L.) and white clover (Trifolium repens L.) at two locations in Poland. All clover stands thinned markedly by spring of the second production year because of infection by Sclerotinia crown and stem rot, but lucerne stands remained dense and this legume produced the highest total yield over 3 or 4 production years. Kura clover yields of 7.2–8.3?Mg?ha^?1 were second to lucerne by the third production year but long-term performance was diminished by stand thinning. Kura clover and white clover had lower fiber concentrations and greater protein concentrations and forage digestibility than red clover and lucerne. Kura clover can be a source of high-quality forage in Europe, but cannot be recommended for use in areas with known Sclerotinia trifoliorum presence until resistance to this pathogen is developed.     

Switchgrass forage yield and biofuel quality with no-tillage interseeded winter legumes in the southern Great Plains

Information is limited on using winter legumes as a source of nitrogen (N) intercropped with switchgrass in the southern Great Plains of the United States. The objectives of this study were to evaluate N contribution of several winter legumes to switchgrass, and to determine the influence of winter legumes on biofuel quality and soil fertility status. Field experiments were conducted at two locations in Oklahoma in which six winter legumes and four rates of N fertilizer were studied over a 3-year period. Winter legumes did not increase switchgrass forage yield, cellulose, lignin, and hemicellulose concentrations at any location. Soil organic matter (OM), nitrate-N (NO₃-N), soil test phosphorus (P), soil test potassium (K), and soil pH remained unchanged. In contrast, applying inorganic N only increased switchgrass yield. This study demonstrated that southern Great Plains may not be conducive to utilizing legumes as the primary N source for switchgrass.     

两种野生绿肥对小白菜生长和营养品质的影响

通过盆栽试验,研究了夏秋两季连续施用野生绿肥植物,即:罂粟科博落回属（Macleaya）（GMⅠ）和壳斗科栎属（Quercu）（GMⅡ）,对小白菜生长及其营养品质的影响。结果表明,与夏季绿肥与尿素配施相比对照显著提高小白菜产量,秋季绿肥Ⅰ的所有处理比对照和单施尿素都能显著提高小白菜的产量;两种绿肥与尿素配施及绿肥Ⅰ单独施用能显著提高小白菜全年的产量。与单施尿素和绿肥加倍单施处理相比,夏季秋季绿肥单施和绿肥尿素配施能显著降低小白菜可食部分硝酸盐含量;秋季各绿肥处理都增加维生素C含量,但夏季差异不明显;夏季秋季各绿肥处理都增加可溶性糖含量,且秋季增加更显著。两种野生绿肥在夏秋季连续施用条件下,秋季能比尿素更有效的提高小白菜产量和营养品质,尤以绿肥Ⅰ的效果最好。     

Effect of nitrogen and wheat residue on cotton (Gossypium hirsutum L.) yield and weed control

Wheat (Triticum aestivum L.) residues and nitrogen (N) management are the major problems in the southern part of Iran where irrigated wheat–cotton (Gossypium hirsutum L.)–wheat rotation is a common practice. A 2-year (2009–2011) field experiment was conducted as a split plot design with four replications at a cotton field (Darab), Fars Province, Iran, to determine the influence of different rates of wheat residue (0%, 25%, 50%, and 75%) incorporation and N rates (150, 200, 300, and 400 kg ha^?1) on weed suppression, yield, and yield components of cotton. Results showed that a higher residue incorporation and a lower N rate improved weed suppression in both years. For treatments receiving 150 kg N ha^?1 and 75% of wheat residues (2250 kg ha^?1), weed biomass and density were significantly lower compared to treatments receiving 400 kg N ha^?1. The highest cotton lint yield (about 2400–2700 kg ha^?1) was obtained by 300 kg N ha^?1 in the absence of residue application, in both years. Incorporation of 25% of wheat residue (750 kg ha^?1) and application of 300 kg N ha^?1 are recommended to guarantee an optimum level of cotton lint yield and weed suppression in a wheat–cotton–wheat rotation in this region.     

狗牙根根系分布特征及其抗拉强度试验研究

以狗牙根为研究对象,就狗牙根根系在土壤中的分布及其抗拉强度进行了初步研究。结果表明,根系密度及根系重量随土层深度(0—40 cm)的增加而减少,其规律均服从指数函数关系分布;根系抗拉力随直径增大而增大,其分布规律均可用二次函数进行拟合;根系的平均抗拉强度为39.349 MPa,约为Ⅰ级钢筋抗拉强度的17%,能产生显著的根系"加筋作用",抗拉强度随直径增大而减小,其规律服从指数函数关系分布。根据狗牙根根系分布特征及抗拉强度特性,其固土护坡作用较大。     

Influence of temperature on nutrient concentration and tetany potential of hardinggrass and tall fescue

Grass tetany (Hypomagnesemia) potential of TAM Wintergreen Hardinggrass and 16 tall fescue lines and varieties was estimated by determining the K, Ca and Mg concentrations in the herbage and the ratio of K/(Ca + Mg) (milliequivalent basis). Data were obtained at four dates during a two‐year period to determine the environmental conditions under which selections should be made to achieve the greatest progress in decreasing the tetany potential of tall fescue and to determine if either of the grasses have high tetany potential in the North Texas area. Hardinggrass had a greater potential to produce grass tetany than tall fescue when grown on the Northern Blackland Prairie of Texas. There were significant differences in K, Ca and Mg concentrations and K/(Ca + Mg) ratio among dates and tall fescue lines. The average temperature for the 30 days before harvest was related to the mineral content and to the K/(Ca + Mg) ratio in all varieties. The K(Ca + Mg) ratio was highest at approximately 18°C but the Mg content fell below the 0.18% required for lactating beef cows when the average temperature for the 30 days before harvest was 22.4°C. Progress could be made in breeding for low grass tetany proneness but selections should be made over a wide range of temperatures considering both the Mg content and ratio of K/(Ca + Mg).     

Influence of phosphorus application on growth,yield and oil quality of linola

Influence of different phosphorus (P) sources on growth, yield and oil quality of linola was evaluated when randomized in complete block design using three replications. Treatments were control (No P), hydropriming, soil phosphorus (50 kg ha^?1), seed inoculation with phosphate solubilizing bacteria (PSB, Bacillus spp.) and seed priming with single super phosphate (2%) alone and combined with reduced soil phosphorus (25 kg P ha^?1). Among treatments, hydropriming and seed inoculation reduced seedling 50% and mean emergence time with highest emergence index, seedling fresh and dry weights and chlorophyll contents. Seed inoculation with soil P (25 kg ha^?1) produced highest seeds per capsule, 100-seed weight, seed and biological yield, harvest index. Maximum oil percentage, low protein contents and high cost benefit ratio with net economic returns were also found for seed inoculation combined with soil phosphorus. Nonetheless, soil phosphorus application can be reduced when seed inoculation with PSB is employed.     

Biochemical traits associated with growing sorghum genotypes with saline water in the field

Abstract

This study was aimed to determine biochemical traits related to higher phytomass production in sorghum genotypes irrigated with saline water. It was also attempted to consider whether or not forage yield production under non-saline conditions could be used as an index for for the selection of high yielding genotypes of sorghum under saline conditions. Forty-five sorghum genotypes were grown under field conditions using saline water or normal irrigation water in two growing seasons in Yazd, Iran. It appeared that salinity tolerance in sorghum genotypes, in addition to local adaption, was highly related to forage yield as well as some biochemical traits as carotenoid concentration, catalase activity, and K⁺/Na⁺ ratio. The screening method based on biochemical traits appeared to be applicable for identification of the salt-tolerant genotypes.     

滴施不同铵硝比例氮肥对马铃薯生长的影响

在盆栽试验条件下,以滴灌施肥方式探讨滴施不同铵硝比例氮肥对马铃薯生长、产量和品质的影响。研究结果表明:在本试验条件下,滴施不同铵硝比例氮肥对马铃薯植株生物量的积累差异不显著;滴施铵态氮肥有利于提高马铃薯块茎中N的浓度,而滴施硝态氮肥有利于提高马铃薯块茎中Ca的浓度;滴施不同铵硝比例氮肥处理马铃薯的淀粉含量、干物质含量、灰分含量等均差异不显著,块茎产量也差异不显著,但马铃薯商品薯比例以滴施铵硝比例为50/50氮肥处理的最高,达到92.01%。