The Effect on Barley Seedlings of Some Inter-Relations of Cations and Anions in a Three-Salt Nutrient Solution

Abstract

Many investigations have been made of the nutrition of plants grown in sand and water culture, and more particularly of the results of the deficiency of one or more specified ions in an otherwise complete nutrient solution. In almost every case, the deficient element was replaced in the nutrient solution by another one.Recently a method was described by HAMNER (4)1 Barley seeds selected for uniformity were planted in quartz sand in glazed 4 x 8-inch self-draining crocks. Ten seeds were planted in each crock and three crocks were used for each point of the triangle. Plants were watered with distilled water until the first leaf was about 5 cm. tall, after which they were watered on alternate days with nutrient solution and were flushed out each week with distilled water.All experiments were repeated twice later in the summer, so that a total of about four thousand plants was used. The investigations were begun in June and continued through September. Plants were grown under ordinarv greenhouse conditions of light and humidity.Two nutrient triangles were used. In the first triangle, three stock solutions, N, S, and P were prepared. Solution N consisted of 0.0045 molar KNO3, 0.0045 molar Mgo(NO3)2, and 0.006 molar Ca(NO3)2. Solu-

Growth Responses of Barley Seedlings in Relation to Potassium and Sodium Nutrition

“…Solution P contained sodiumidihydrogren phosphate, monobasic magnesium phosphate, and monobasic calciullm phosphate. Finely powdered calcium sulphate dissolved readilyV when slowly sifted into solution S. This was easier than the method previously reported (15 (15), brought about in the presence of potassiumi. Nevertheless, at the timiie of harvest the planits were a lighter green than nornal, this undoubtedly being the first sign of potassium deficiency.…”

The influence of different P, NH+ 4 and NO− 3 supply levels on the yield and P and Ca relationships in wheat

“…J. Plant Soil 1988, 5(3) Table 5 Percentage Ca in root and top growth of wheat at varying P and NH4 +:N0 3 -supply levels Several workers have found that N0 3 -reduces the detrimental effect of too high a P supply (Hamner, 1940;Mullison, 1941;Claassens & Folscher, 1980;Grobler & Folscher, 1980;Claassens & Folscher, 1985). According to the results of this experiment, the highest P supply level tends to reduce top growth especially with reducing N0 3 -and increasing NH4 + supply (P 4 , Table 2).…”

Die invloed van fosfor, nitraat en ammonium op die opname en vervoer van stikstof en fosfor en op die groei van koring

“…Daarenteen het hulle gevind dat hoe P-voorsiening nadelig is vir groei, weens die moontlike rol van 'n hoe P-status in die plant by ontkoppeling van fosfaat in die metabolismeproses. Verder het hulle bevestig dat hoe N03-voorsiening die toksiese effek van hoe P teewerk soos ook deur ander navorsers bevind is (Hamner, 1940;Mullison, 1941;Claassens & Folscher, 1980). Loneragen, Grunes, Welsch, Aduayi, Tengah, Lazar & Carey (1982) vermeld dat Zn ook P-toksisiteit teewerk deurdat dit die opname en vervoer van fosfaat van die wortels na die bogroei verminder.…”

“…Hierdie resultate dui daarop dat hoe N03-voorsiening die vervoer van P vanaf die wortels na die bogroei beperk sodat die P-konsentrasie in die bogroei nie baie hoog word nie, terwyl met N~ dit nie die geval is nie. Dit kan ook verklaar waarom verskeie navorsers vermeld dat N03 die nadelige effek van te hoe P-voorsiening teewerk (Hamner, 1940;Mullison, 1941;Grobler, 1976;Claassens & PCIlscher, 1980). Indien die vergeJing wat by hoe P-voorsiening waargeneem is aan 'n oormaat P toegeskryf word, verklaar die resultate ook die afname in chlorose met 'n afname in die P-status van die bogroei.…”