Evaluation of Agronomic and Environmental Soil P Test Methods in a Network of Hungarian Long‐Term Field Trials

Abstract

Winter wheat shoot weight and phosphorus (P) concentrations, corn leaf weight and P concentrations, and soil AL, Olsen, H₂O, Bray 1, Pi (Fe-oxide impregnated paper strip) and AERM (anion exchange resin membrane) contents were determined in a network of uniform Hungarian national long‐term field trials. P application had a significant effect on soil P test values at different P levels and sites. The relationship between the different soil P test methods was studied separately for different soil groups (all, acid, and calcareous soils). Corn leaf weight was influenced by the sites much more than by soil P supply level, whereas corn leaf P percentage was influenced by both sites and P levels. For winter wheat, both sites and soil P levels had a positive effect on wheat shoot weight. Wheat shoot P percentage was influenced by the soil P supply much more than by the sites. Correlation between corn leaf P percentage and the Pi or AERM extractable P and between wheat shoot P percentage and the Pi and AERM P values was logarithmic.     

An evaluation of Colwell‐P as a measure of plant‐available phosphorus in soils of volcanic and non‐volcanic origins in the highlands of Papua New Guinea

Various soil test methods including Olsen, Colwell, Bray and Truog have been used to assess the levels of plant‐available P (PAP) in soils situated in the highlands of Papua New Guinea (PNG). Up until now, though, there has been no guarantee that these tests provide valid assessments of PAP in these somewhat atypical organic matter‐rich tropical soils. Furthermore, the critical soil‐P concentrations associated with the tests have been based on studies conducted elsewhere in sub‐tropical and temperate latitudes and as such may or may not be valid for soils or cropping situations in PNG. Soil (Colwell)‐P and leaf‐P data collected during a recent survey of sweet potato gardens in the highlands of PNG were therefore used to determine if useful relationships existed between these variables for different groups of soils, and if they do, to use these relationships to evaluate critical soil Colwell‐P concentrations corresponding to a known critical concentration of P in sweet potato index leaf tissue. Separate, highly significant linear relationships were obtained between leaf‐P and Colwell‐P for soils of volcanic and non‐volcanic origins. Based on these relationships, the critical Colwell‐P concentration for volcanic soils was found to be four times greater than that for non‐volcanic soils, presumably because much of the P extracted from the former soils with alkaline sodium bicarbonate had been chemically ‘fixed’ via sorption and precipitation reactions with sesquioxides and rendered unavailable to plants at ambient soil pH. These critical Colwell‐P concentrations if adopted as benchmark values for the soil groups in question should ensure that the results of future soil fertility surveys involving Colwell‐P assessments are correctly interpreted.     

玉米连作为主垄作少耕新农作制施肥技术的探讨

本文介绍了以玉米连作为主的垄作少耕新农作制施肥技术的特点，以及根茬秸秆还田技术和农家肥，化肥的施用方法，通过试验证明，吉林省西部半干旱地区化肥于秋季或春季一次微基肥施用是可行的，在目前生产上，施用化肥可与秋季或春季的灭茬，深松，起垄同步进行。     

包装玉米长期安全储藏试验

在华南地区高温高湿环境下，在尚不具备机械通风设备的楼房仓内进行玉米包装大堆保管。采用合理的剂量和熏蒸方法，保持粮堆内较长时间的PH3有效浓度，抑制了玉米的呼吸强度和微生物、害虫的生长繁殖，确保了玉米长期安全储藏，保持了较好的储粮品质。     

青贮玉米的发展前景与栽培技术

青贮玉米是我市近年来新开发利用的种植与养殖业相结合的产业结构调整发展链 ,把两者有机地结合起来互促共同发展 ,是提高两个效益的基础 ,高产、优质、低耗栽培技术的推广普及是产业结构链发展的起点 ,高产栽培的配套技术是 :选用优良品种——白顶 ;合理密植 ( 6～ 7)× 1 0 4· hm- 2 ;肥料运筹科学合理 ,基肥∶苗肥∶穗肥∶粒肥 =3∶ 1∶ 5∶ 1     

Evaluation of Root Sink Ability of Sweet Potato (Ipomoea batatas Lam.) Cultivars on the Basis of Enzymatic Activity in the Starch Synthesis Pathway

Activities of five enzymes, sucrose synthase (SUS), uridine 5'-diphosphate glucose pyrophosphorylase (UDPGPPase), fructose-1,6 bisphosphatase (FBPase), adenosine 5'diphosphate glucose pyrophosphorylase (ADPGPPase) and starch synthase (STS), in the metabolic pathway of starch synthesis, were compared between two sweet potato ( Ipomoea batatas Lam.) cultivars, Koganesengan (C.V.KOG, a recently released high yield cultivar) and Tsurunasigenji (C.V.TSU, an old, local cultivar with poor yield). The measurements were carried out using the root samples (tuberous, thick and fibrous roots) harvested at the fast tubering stage. Of the five enzymes, SUS, ADPGPPase and STS showed high activities in the tuberous root, particularly in that of C.V.KOG, and a similar trend was observed for activities of these enzymes on a protein basis. The increased activity of the three enzymes is considered to be one of the characteristics in a high yield cultivar, allowing the root to function effectively as a starch synthesis and storage organ.     

Ertragsstruktur alter und neuer Winterweizensorten unter dem Aspekt der Einlagerung und Remobilisation von Fruktanen im Weizenhalm

Yield components in old and new german winter wheat varieties with respect to the storage and remobilization of fructan in the wheat stem
Yield components and changes in carbohydrate content of four old german winter wheat varieties, bred before 1950, were compared with six new varieties over two years in field trials. In both years the old varieties built up more biomass than the new varieties. In the latter a better harvest-index (0,56) as compared to the old varieties (0,43) was obtained, resulting in higher grain yields for the new varieties. Changes in water-soluble carbohydrate (WSC) content were mainly due to variations in fructan content. Maximum of fructan content was mostly reached at the stage of early milk ripeness. In the new varieties a faster and more complete remobilization of fructan occurred; especially in the year with the short grainfilling period.     

甜荞品种温度生态特性的研究

甜菜品种对温度的反应特性研究结果表明：来自全国荞麦主栽区的12个品种可分成4种类型；（1）强敏感型；（2）敏感型；（3）弱敏感型；（4）迟钝型，对低温敏感性强的品种的生物学起点温度比敏感性弱的品种高。     

夏红薯施用惠满丰有机复混肥增产效果研究

夏红薯施用惠满丰有机复混肥300，600，900kg/hm^2后，较不施肥对照增产鲜薯4183.5-6516.0kg/hm^2，增产幅度24.8%-38.6%，平均31.8%。与施用化肥相比，增产鲜薯1716.0-4048.5kg/hm^2，增幅8.9%-20.9%，增产效果极为显著。在本试验条件下，无论等养分量与否，惠满丰有机复混肥产化肥增产效果显著，从增产及效益等方面综合评估，惠满丰有机复混肥的适宜施用量是600kg/hm^2左右。     

冬小麦对麦红吸浆虫抗性机制研究初报

在虫圃鉴定1254份材料的基础上，对10个不同抗性品种进行了抗性机制研究。研究表明，小麦抗麦红吸浆虫抗性品种植株高，穗部密度大，旗叶长而窄，内颖尖隐伏数多，内颖弧口宽，植株茎、叶和颖壳南程度高，有被毛，颖壳硬而厚。测定了不同抗性品种（系）的未害子粒和被害粒中某些生化物质，明确了小麦品种对吸浆虫的抗性是以诱导抗性为主的多因子综合抗性。总酚、单宁和可溶性糖是影响其生化抗虫性的关键因子，总酚尤为重要。