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41.
在大田栽培条件下,研究了施钾量对北沙参生长、产量和品质的影响。结果表明,增施钾肥对北沙参株高的生长有一定的促进作用,可显著提高北沙参的叶面积系数,和在生长后期维持较高的绿叶面积,有利于北沙参根的伸长,和地上部干重、根干重的积累。因而增施钾肥可显著提高北沙参产量,同时显著提高其有效成分多糖、总皂甙含量,但是施钾量超过210 kg/hm2后产量不在显著增加,说明从施肥效益上应适量施用钾肥。  相似文献   
42.
Models for cycles for organic matter and nutrients element (N, P, K, Ca and Mg) are presented for the agroforestry systems of cacao (Theobroma cacao) withCordia alliodora orErythrina poeppigiana in Turrialba, Costa Rica. For the models, system reserves (soil, humus, vegetation divided into leaves, branches, stems, fine roots, fruits) and transference between compartments (production and decomposition of litter residues) inputs (fertilizer, rainfall) and outputs (harvests) of the system are considered. The implications of the models are discussed in detail. Aspects of net primary production in the systems studied are considered. N fixation is calculated on the basis of balances. Analysis of soil water showed high variations that coincided with rainfall patterns and pruning of theE. poeppigiana. For part I see Vol. 4, No. 3, 1986 For part II see this issue Agroforestry Project, CATIE/GTZ (Tropical Agricultural Research and Training Center/Gesellschaft für Technische Zusammenarbeit), Turrialba, Costa Rica  相似文献   
43.
Models for cycles for organic matter and nutrients element (N, P, K, Ca and Mg) are presented for the agroforestry systems of cacao (Theobroma cacao) withCordia alliodora orErythrina poeppigiana in Turrialba, Costa Rica.For the models, system reserves (soil, humus, vegetation divided into leaves, branches, stems, fine roots, fruits) and transference between compartments (production and decomposition of litter residues) inputs (fertilizer, rainfall) and outputs (harvests) of the system are considered.The implications of the models are discussed in detail.Aspects of net primary production in the systems studied are considered.N fixation is calculated on the basis of balances. Analysis of soil water showed high variations that coincided with rainfall patterns and pruning of theE. poeppigiana.For part I see Vol. 4, No. 3, 1986 For part II see this issueAgroforestry Project, CATIE/GTZ (Tropical Agricultural Research and Training Center/Gesellschaft für Technische Zusammenarbeit), Turrialba, Costa Rica  相似文献   
44.
氮磷钾对绿玉菊生长的影响   总被引:1,自引:0,他引:1  
采用水培方式,探讨不同浓度水平氮、磷、钾对绿玉菊生长的影响。分析了不同浓度氮、磷、钾处理下绿玉菊的株长、根长、叶绿素含量、丙二醛含量的关系。结果表明绿玉菊的株长和叶绿素含量随氮肥浓度的增加而增长;处理5(含氮7.5mmol.L-1,含磷0.2mmol.L-1,含钾3mmol.L-1)最符合绿玉菊水培生长要求。  相似文献   
45.
The agroforestry systems of cacao (Theobroma cacao) under laurel (Cordia alliodora) and cacao under poro (Erythrina poeppigiana) were studied at CATIE, Turrialba, Costa Rica. An inventory was taken of the organic matter and nutrients (N, P, K, Ca, and Mg) separating the species into their compartments (leaves, branches, trunks and roots). Studies of the litter and of the mineral soil (0–45 cm) yielded these results: Patterns of nutrient accumulation are discussed in relation to the characteristics of these agroforestry systems.  相似文献   
46.
During 7 years (1979–1985) cacao harvests (beans and husks) have been recorded for the agroforestry systems ofTheobroma cacao underCordia alliodora andErythrina poeppigiana shade trees. The mean oven dry cacao yields were 626 and 712 kg.ha−1.a−1 cocoa beans underC. alliodora andE. poeppigiana respectively. Harvests have gradually increased over the years and the plantation has now reached maturity. Annual extraction of N, P, K, Ca and Mg in fruits, which is relatively small, was calculated on the basis of chemical analyses. The following average values were found (kg.ha−1.a−1): At the age of 8 years, theC. alliodora trees have reached 26.7 cm diameter (DBH) and 14.0 m in height. Mean annual growth (from age 5 to 7) is 14.6 m3.ha−1.a−1. Natural plant residue production has been measured for 4 years (Nov. 1981–Oct. 1985). UnderE. poeppigiana it has reached a value of 8.91 t.ha−1.a−1 and underC. alliodora 7.07 t.ha−1.a−1. The shade trees have contributed 57 and 47% respectively. Transference and decomposition rates are high and important in the nutrient cycles. The nutrient content of the litter was analysed and corresponding average yearly transfers were (kg.ha−1.a−1): For part I see Vol. 4, No. 3, 1986. Agroforestry Project, CATIE/GTZ (Tropical Agricultural Research and Training Center/Gesselschaft für Technische Zusammenarbeit), Turrialba, Costa Rica  相似文献   
47.
48.

Background

Neonatal diarrheic calves have a clear negative potassium balance because of intestinal losses and decreased milk intake but in the presence of acidemia, they usually show normokalemic or hyperkalemic plasma concentrations.

Objectives

To assess whether marked hypokalemia occurs in response to the correction of acidemia and dehydration and to identify factors that are associated with this condition.

Animals

Eighty‐three calves with a clinical diagnosis of neonatal diarrhea.

Methods

Prospective cohort study. Calves were treated according to a clinical protocol using an oral electrolyte solution and commercially available packages of 8.4% sodium bicarbonate, 0.9% saline and 40% dextrose infusion solutions.

Results

The proportion of hypokalemic calves after 24 hours of treatment (19.3%) was twice as great as it was on admission to the hospital. Plasma K+ after 24 hours of treatment was not significantly correlated to venous blood pH values at the same time but positively correlated to venous blood pH values on admission (= 0.51, < .001). Base excess on admission (Odds ratio [OR] = 0.81, 95% confidence interval [CI] = 0.70–0.94), duration of diarrhea (OR = 1.37, 95% CI = 1.05–1.80), milk intake during hospitalization (OR = 0.54, 95% CI = 0.37–0.79) and plasma sodium concentrations after 24 hours (OR = 1.12, 95% CI = 1.01–1.25) were identified to be independently associated (< .05) with a hypokalemic state after 24 hours of treatment.

Conclusions and Clinical Importance

Findings of this study suggest that marked depletion of body potassium stores is evident in diarrheic calves that suffered from marked metabolic acidosis, have a low milk intake and a long history of diarrhea.  相似文献   
49.
通过田间小区试验研究了不同N、K肥料配比对酸性和碱性土壤上两个莴笋品种(科兴 3 号和双尖莴笋)产量及品质的影响.结果表明,不同土壤上施用不同N、K配比肥料对双尖莴笋和科兴 3 号的产量影响不同.在酸性土壤上,对照(N15K10)是适宜两种莴笋高产的最佳N、K肥配比处理.在碱性土壤上种植双尖莴笋时,可以考虑在对照基础上适当地降低N肥用量.在碱性土壤上两种莴笋的产量均高于酸性土壤.减N和增K处理有利于降低莴笋的硝酸盐含量.在酸性土壤上莴笋中的硝酸盐含量高于碱性土壤.莴笋采收后期茎的硝酸盐含量高于叶片.不同施肥处理对两种土壤上科兴3号和双尖莴笋营养品质的作用不一致.在酸性土壤上增施K肥或提高N肥的用量对莴笋营养品质的改善更有效果.莴笋的Vc含量以叶片>茎,且酸性土壤>碱性土壤.除双尖莴笋在增K处理(N15K15、N20K15)中茎的可溶性糖含量表现为酸性土<碱性土以外,其他处理莴笋茎叶中的可溶性糖均为酸性土>碱性土.不同处理莴笋的氨基酸含量均表现为茎>叶.  相似文献   
50.
Frozen bread dough: Effects of freezing storage and dough improvers   总被引:1,自引:0,他引:1  
This review focuses on the effects of freezing storage on the microstructure and baking performance of frozen doughs, and provides an overview of the activities of dough improvers, including emulsifiers, hydrocolloids and other improvers used in frozen dough applications. The overall quality of bread baked from frozen dough deteriorates as the storage of the dough at sub-zero temperatures increases due to several factors which are discussed. Lipid-related emulsifiers such as diacetyl tartaric acid esters of mono and diglycerides and sucrose esters employed as anti-staling agents, dough modifiers, shortening sparing agents, and as improvers for the production of high-protein bread have also been employed in frozen doughs. Hydrocolloids are gaining importance in the baking industry as dough improvers due to their ability to induce structural changes in the main components of wheat flour systems during breadmaking steps and bread storage Their effects in frozen doughs is discussed. Other dough improvers, such as ascorbic acid, honey and green tea extract, are also reviewed in the context of frozen doughs.  相似文献   
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