Sodium fertilizer application to pasture. 2. Effects on dairy cow production and behaviour

Fifty-four lactaling dairy cows were grazed for 24 weeks on pasture receiving 0 (Nil), 32 (Low) or 64 (High) kg Na ha^-1 yr^-1 and with (+) or without (-) 100g NaHCO₃ buffer included in a maize gluten concentrate supplement. Cattle grazed the Na-fertilized pasture to a lower height, particularly in the High treatment. Cows grazing pasture with Na fertilizer produced more milk, and milk fat concentration increased in direct proportion to amount of Na fertilizer applied and with NaHCO₃. This increase was greatest in early season. Milk protein concentration was not affected by Na fertilizer application or NaHCO₃ buffer addition. Milk lactose concentration was increased by Na fertilizer application but not by NaHCO₃ supplementation. Cows in the Na-applied treatments gained more live weight but there was no effect of treatment on condition score change. Grazing time and drinking frequency increased linearly with increasing pasture Na. Ruminating time and biting rate were similar at the Low and High treatments and greater than the Nil treatment. NaHCO₃, supplementation increased drinking frequency and decreased the rate of concentrate intake. Cow reproductive performance was not significantly affected by Na fertilizer application. During the residual period, cows that had previously grazed the Na-fertilized pasture had reduced milk fat and protein contents.     

不同剂量矮壮素处理对棉花农艺性状及产量品质的影响

为探索在南疆使用植物生长调节剂矮壮素（质量分数为50%,水剂）在棉花控旺防徒长、增产等方面的调控效果,于2020年以新陆中82 号为研究对象,采用随机区组试验设计,设置对照药剂25%（质量分数）甲哌水剂180 mL·hm^－2、人工打顶和清水喷雾为对照处理,研究了喷施矮壮素60（低剂量）、90（中剂量）、120（高剂量）、180（超高剂量）mL·hm^－2,对棉花顶芽、农艺性状、产量和品质的影响。结果表明,不同剂量矮壮素处理均能抑制顶点生长,降低株高,使棉花株型紧凑。其中,使用50%矮壮素水剂120和180 mL·hm^－2处理对控制棉花旺长的效果最明显：棉花顶芽枯死率达到100%,采收期棉花株高为74～79 cm,显著低于对照药剂处理,与人工打顶效果无显著差异。50%矮壮素高剂量和超高剂量处理可以使棉花株型更紧凑,并且均具有增产效果。因此,在生产应用中,可以使用50%矮壮素水剂120～180 mL·hm－2对棉花进行化控。     

不同浓度沼液浸种对杂交水稻种子发芽率、成秧率的影响

高活力的新种采用沼液原液浸种比清水浸种发芽率提高4．2％,成秧率提高10．7％,且出苗快,苗壮根粗,叶色浓绿。秧苗素质明显比对照好,是一项新型的种子处理技术,且技术简便、安全、效果好,值得大力推广。     

Potency of microbial inocula from bovine faeces and rumen fluid for in vitro digestion of different tropical forage substrates

In vitro ruminal fermentation techniques rely on the availability of fistulated ruminants for rumen fluid (RF), a major constraint for resource‐poor institutions. An alternative would be to use faecal microbes. This study was therefore designed to compare the potency of fresh bovine faeces against RF as sources of microbial inocula for fermenting six contrasting tropical forages using the Tilley and Terry (Journal of British Grassland Society, 18 , 104–111) technique. Faecal inocula were prepared at concentrations of 250 g (Faec250), 300 g (Faec300), 350 g (Faec350), 400 g (Faec400) and 450 g (Faec450) fresh cow faeces per litre bicarbonate buffer. In vitro organic matter digestibility (IVOMD) increased with increasing concentration of faeces at 12‐, 24‐ and 48‐h incubation intervals. All faecal inocula except Faec450 had lower potency when compared with RF at all incubation intervals. Digestibility of forage substrates with Faec450 (533 ± 23 g kg^?1 DM IVOMD) was comparable to RF (566 ± 5 g kg^?1 DM IVOMD) after 48‐h incubation. Faec450 showed greater potency on more fibrous and low‐protein substrates than RF. The coefficient of determination of the regression models for predicting 12‐, 24‐ and 48‐h RF IVOMD from Faec450 were 0·914, 0·75 and 0·756 respectively. It was concluded that inocula prepared from 450 g cow faeces demonstrated great potential as a substitute and predictor for RF in 48‐h IVOMD assays of tropical forages.     

Interactions of nanobubbles with bovine serum albumin and papain films on gold surfaces

Nanobubbles formed on monocrystalline gold/water interface by means of the ethanol-to-water solvent exchange were exposed to the solutions of either bovine serum albumin or papain proteins. Both proteins do not change the position of nanobubbles in water, as observed by in situ tapping mode atomic force microscopy imaging before and after the introduction of the protein. The aqueous environment was subsequently replaced by ethanol. While all nanobubbles were found to dissolve in ethanol in the presence of bovine serum albumin, most of them survived when papain was employed. The protective ability of papain was ascribed to its resistance towards the protein denaturation in aqueous solutions of ethanol. The authors employed in situ atomic force nanolithography to investigate the nanomorphology of the papain/nanobubble assemblies in ethanol.     

Effect of different Cs concentrations on overall plant growth and Cs distribution in soybean

The absorption and dynamics of Cs in crops can be measured and examined using not only ¹³⁷Cs but also ¹³³Cs, a stable isotope which can be analyzed in a regular laboratory. When ¹³³Cs is used, however, the concentration of added ¹³³Cs must be set higher than that in the soil solution due to the detection sensitivity of inductively coupled plasma optical emission spectrometry (ICP-OES). There is concern that such high Cs concentrations may adversely affect crops and interfere with Cs dynamics. Using soybean as a test product, we first examined the initial growth of soybean cultivated under exposure to solutions with different ¹³³Cs concentrations. In combination with each ¹³³Cs concentration, two potassium (K) concentrations were tested. Results show that at both K concentrations, growth was inhibited under ¹³³Cs concentrations higher than 1 × 10^?3 mol L^?1. Soybeans cultivated at ¹³³Cs concentrations higher than 1 × 10^?6 mol L^?1 can be subject to ICP-OES for measuring ¹³³Cs concentrations in the plant tissue. Next, soybeans cultivated under different ¹³³Cs concentrations throughout growth were examined for Cs distribution in the plants. The distribution patterns of Cs in soybean plants cultivated at ¹³³Cs concentrations equivalent to those found in the soil were almost identical to those in plants cultivated at measurable ¹³³Cs concentrations (1 × 10^?6–1 × 10^?4 mol L^?1) as measured with ICP-OES. Therefore, in our investigation, ¹³³Cs distribution in soybean plants treated with up to 1 × 10^?4 mol L^?1 was considered equivalent to that in plants cultivated in the field.     

Effects of elevated CO2 concentration on growth and photosynthesis of Chinese yam under different temperature regimes

Chinese yam (‘yam’) was grown at different carbon dioxide concentrations ([CO₂]), namely, ambient and elevated (ambient + 200 μmol mol^?1), under low- and high-temperature regimes in summer and autumn, separately. For comparison, rice was also grown under these conditions. Mean air temperatures in the low- and high-temperatures were respectively 24.1 and 29.1 °C in summer experiment and 20.2 and 24.9 °C in autumn experiment. In summer experiment, yam vine length, leaf area, leaf dry weight (DW), and total DW were significantly higher under elevated [CO₂] than ambient [CO₂] in both temperature regimes. Additionally, number of leaves, vine DW, and root DW were significantly higher under elevated [CO₂] than under ambient [CO₂] in the low-temperature regime. In autumn experiment, tuber DW was significantly higher under elevated [CO₂] than under ambient [CO₂] in the high-temperature regime. These results demonstrate that yam shows positive growth responses to elevated [CO₂]. Analysis of variance revealed that significant effect of [CO₂] × air temperature interaction on yam total DW was not detected. Elevated-to-ambient [CO₂] ratios of all growth parameters in summer experiment were higher in yam than in rice. The results suggest that the contribution of elevated [CO₂] is higher in yam than in rice under summer. Yam net photosynthetic rate was significantly higher under elevated [CO₂] than under ambient [CO₂] in both temperature regimes in summer. Elevated [CO₂] significantly affected on the rate in yam but not in rice in both experiments. These findings indicate that photosynthesis responds more readily to elevated [CO₂] in yam than in rice.     

不同施肥种类与数量对大豆产量的影响

在氮磷钾配合施用条件下,大豆产量大幅度增加,大豆产量可达3260kg／hm^2;磷钾配合施用条件下,产量可达3160kg／hm^2。施用氮肥、磷肥的增产效果显著、肥效高。     

Effects of predicted milk yields sustained by grazed grass on dairy cow performance and concentrate requirements throughout the grazing season

The objective of this study was to examine the effects of predicted milk yields sustained by grazed grass (‘Milk‐from‐Grass’: LOW, MED or HIGH) and Parity (primiparous or multiparous) on the performance and concentrate requirements of grazed Holstein‐Friesian dairy cows offered concentrates on a ‘feed‐to‐yield’ basis during the grazing season. The mean Milk‐from‐Grass values assigned to cows in the LOW, MED and HIGH treatment groups (sixteen multiparous and eight primiparous cows per group) during the experiment (24 May to 2 October; 131 d) were 12·7, 15·4 and 18·1 kg cow^?1 d^?1, respectively. Concentrate allocations were adjusted every two weeks (approximately) based on individual cows’ milk yields, and concentrate was offered at a rate of 0·45 kg for each kg of milk produced above the assigned Milk‐from‐Grass value at that time. Increasing Milk‐from‐Grass from LOW to MED to HIGH decreased both the mean daily concentrate allocations (4·90, 3·17 and 1·79 kg cow^?1 d^?1, respectively) and milk yields (23·8, 21·8 and 19·0 kg cow^?1 d^?1) of the cows. Cows in the LOW treatment group had lower mean and final (i.e. at the end of the study) BCS and LW than those in the MED or HIGH groups. The effects of Milk‐from‐Grass were similar for both primiparous and multiparous cows.     

Effect of flax seeds and date palm leaves extracts on serum concentrations of glucose and lipids in alloxan diabetic rats

The aim of the present investigation was to examine the effect of Flax Seeds (FS) and Date Palm Leaves (DPL) extracts on the concentration of serum glucose and lipids in alloxan diabetic rats. Rats were divided into six groups, normal control rats (without treatment with either FS or DPL), normal control rats treated with either FS or DPL extract for four weeks, diabetic control rats and diabetic rats treated with either FS or DPL extract for four weeks. The concentration of glucose in diabetic rats treated with FS (D+FS) for four weeks was significantly decreased from 17.20 +/- 2.33 to 8.14 +/- 0.54 mmol L(-1) (p < 0.001). Serum total cholesterol concentration (TC) of diabetic rats treated with either FS or DPL extract showed significant decrease by 40 and 31% respectively in the fourth week. Also, serum low density lipoprotein cholesterol (LDL-C) concentration was significantly decreased after two weeks of treatment (p < 0.001 and p < 0.01, respectively). However, no significant changes were obtained in serum high density lipoprotein cholesterol (HDL-C) concentration. Results of the present study showed that FS extract has a hypoglycaemic effect against alloxan diabetic rats. Present findings also showed that treatment of alloxan diabetic rats with either FS or DPL extract significantly decreased serum concentration of TC and LDL-C. Present findings suggest that both of FS and DPL extracts could have a protective effect against diabetes complications as well as against hyperlipidemia through improvement of lipid profile.     

温度对大豆蚜生长发育和繁殖的影响

在5种不同温度条件下研究了大豆蚜有效积温、发育起点温度、繁殖力等生物学特性。结果表明,大豆蚜各虫态的发育历期随着温度的升高而显著缩短,若虫发育明显受到低温抑制。10℃下发育历期最长为22.08d,15、20、25、30℃分别为14.04,10.67,9.92和6.71d。相对低温同时也抑制大豆蚜繁殖能力,10℃下平均产仔量和日产仔量均为最小,分别为15.73头和1.23头/d。 20和25℃下大豆蚜繁殖力较强,平均每天产仔量分别为27.87和27.36头。通过直线回归分析,得出大豆蚜1龄若虫发育起点温度最高为2.0268℃,有效积温为38.4216日度,大豆蚜世代发育的起点温度为1.6587℃,有效积温为202.7879日度。     

不同土壤环境对甜菜产质量的影响

试验结果表明,非病地比病地平均提高根产量、含糖率、产糖量分别为12230.6kg/hm、4.46度、3122.4kg/hm2;t测验分析表明,不同土壤环境对甜菜产质量具有不同程度的影响,其大小顺序是含糖率>产糖量>根产量,分别有94.1%、84.7%和50.7%的材料因不同土壤环境而达到显著或极显著差异。方差分析结果显示,在病地参试材料的根产量、产糖量的差异显著性与非病地的基本同步,而含糖率差异显著性却不完全同步,病地更能造成材料间含糖率的显著或极显著差异。两种地块导致单胚材料、饲料甜菜的根产量和产糖量差异悬殊。     

不同种衣剂对大豆产量及品质的影响

2006-2007年采用5种生产上不同类型种衣剂处理高油大豆品种垦农19进行田间试验,研究对大豆生长发育及产量和品质的作用.结果表明,增加了株高和根瘤数,有一定的增产作用并对粗蛋白质、粗脂肪的影响不明显.各处理增产幅度2%～16%, 处理C(火秧灭2号)、D(施特灵)比对照分别增产16%、12%,其中处理C比对照增产显著.不同种衣剂处理蛋白质含量相差0.7个百分点,脂肪含量相差0.2个百分点,差异不显著.     

Effects of a stay-green trait on the concentrations and stability of fatty acids in perennial ryegrass

Abstract Three experiments were conducted to evaluate the effect of a stay‐green trait in perennial ryegrass (Lolium perenne) on concentrations of fatty acids as well as their susceptibility to peroxidation during wilting and to biohydrogenation by rumen bacteria. Fatty acid concentrations were recorded in stay‐green and corresponding normal perennial ryegrass selection lines over eight cuts during 1998. There was a progressive increase in total fatty acid concentrations [from 20·8 to 34·6 g kg^?1 dry matter (DM)] and the proportion of fatty acids as α‐linolenic acid (from 0·62 to 0·70 g g^?1) from early to late season. A second study compared fatty acid concentrations in stay‐green and normal herbage that was wilted for up to 48 h. There was a loss of 0·2–0·3 g g^?1 fatty acids during 48 h of wilting and a small reduction in the rate of loss of α‐linolenic acid in stay‐green perennial ryegrass compared with normal herbage (0·223 vs. 0·290 g g^?1 lost after 48 h). Stay‐green and normal perennial ryegrasses were offered to grazing lambs in a third study. Higher concentrations of trans‐vaccenic acid and conjugated linoleic acid in plasma from lambs offered less mature grass in the pre‐experimental period than during the experiment are considered to reflect a greater supply of precursor (linoleic acid). There were higher concentrations of conjugated linoleic (0·0070 vs. 0·0039 g l^?1) and linoleic (0·092 vs. 0·070 g l^?1) acids, without an increase in trans‐vaccenic acid, in plasma from lambs grazing stay‐green perennial ryegrass than normal perennial ryegrass. This suggests that the stay‐green trait affected the rate of degradation of fatty acids in the rumen. These results demonstrate the potential for obtaining proportionately large differences in fatty acid profiles of ruminant products by altering grassland management.     

Effects of elevated CO2 concentration on bulbil germination and early seedling growth in Chinese yam under different air temperatures

The present study investigated the effects of elevated carbon dioxide concentration ([CO₂]) and air temperature on the germination of seed bulbils and the seedling vigour of two Chinese yam lines. Plants were grown under two [CO₂] levels, ambient and elevated (ambient + 200 μmol mol^?1), and two mean air temperature regimes, 22.2 °C (ambient + 1.4 °C) and 25.6 °C (ambient + 5.2 °C). Elevated [CO₂] did not affect bulbil germination under both air temperature regimes. During the early growth stage, the dry weight (DW) of leaves, vines, shoots, roots, belowground parts (roots + tubers) and whole plants were higher under elevated [CO₂] than ambient [CO₂] for both lines under the low- and high-temperature regimes. The values of vigour indexes (index I = germination % × seedling length and index II = germination % × seedling DW) were also higher under elevated [CO₂] than ambient [CO₂] for both lines. These results indicated that Chinese yam seedlings respond positively to elevated [CO₂] during the early growth stage. The above:belowground DW ratios were lower under elevated [CO₂] than ambient [CO₂] in seedlings with very small new tubers for both yam lines, indicating that elevated [CO₂] strongly affected the root growth in the early growth stage. The DWs of post-treatment seed bulbils were higher in the elevated [CO₂] under both air temperature regimes. The results showed that Chinese yam used a smaller amount of the reserves in seed bulbils under elevated [CO₂] than under ambient [CO₂].     

蓖麻不同种植密度对群体生育动态的影响

试验表明,蓖麻在不同种植密度下,株高、叶面积系数、净同化率等均有不同程度的变化,并对群体产量有一定影响。２０００～２１００ｋｇ／ｈｍ２的蓖麻高产群体指标以密度３３０００～４３７００株／ｈｍ２,灌浆成熟期株高２３０～２４０ｃｍ,花果期叶面积系数２．０～２．５,开花期净同化率７．９～８．４ｇ／ｍ２·ｄ为宜。     

耕作方式对连作大豆生长发育及产量的影响

采用秋旋耕起垄、秋深松旋耕起垄、春旋耕起垄和春顶浆打垄4种土壤耕作方式,进行田间大区试验,以探讨土壤耕作方式对连作大豆生长发育及产量的影响。试验结果表明,秋旋耕起垄和秋深松旋耕起垄出苗率高于春旋耕起垄和春顶浆打垄,出苗率均达85%以上,秋整地大豆生育期间干重、根瘤重和叶面积指数均高于春整地,秋旋耕起垄大豆根际微生物总数最多,细菌和放线菌数量明显高于春顶浆打垄。秋季整地地下害虫——蛴螬（Holotrichia diomphalia Bates）危害率比春季整地低10%左右,春顶浆打垄危害率高达34.3%。秋整地大豆的灰斑病发生程度、籽粒紫斑粒率和虫食率均低于春整地,秋整地产量较春整地增产16%以上,从本试验可以看出黑龙江省黑土平原区秋整地对连作大豆效果更好。     

ClayF缓释复肥对小麦生长发育的影响

ClayF缓释复肥是一种包含丰富中、微量元素的缓释粘土矿物包膜肥料,具有多种生物活性.盆栽试验结果表明:红壤旱土施用适量的ClayF缓释复肥可有效提高小麦的根重、株高、有效分蘖、穗长、实粒数、千粒重和地上部分干重,籽粒产量比对照增加12%.适量的ClayF缓释复肥同时能增强小麦对氮、磷、钾养分的吸收,促进氮、磷、钾养分向小麦籽粒转运.