Root and crop growth of oats as affected by the length of periods of high water-table.

The influence of the duration of a high water-table on root and shoot growth of oats in an early growth stage was studied. Root wt., depth of rooting and number of nodal roots with a length of < 10 cm reacted favourably on a low water-table. In this experiment shoot growth, however, hardly reacted to better root growth. This meant that the plants with restricted root growth could absorb water and nutrients as well as those with larger root systems. The fertilization of the top 0-25 cm of soil could have been an important factor in this report. (Abstract retrieved from CAB Abstracts by CABI’s permission

The effect of nitrogen on the root and shoot development of Lolium multiflorum var. westerwoldicum.

Westerwolds ryegrass was grown in tubes on artificial soil profiles at N rates equivalent to 25, 50 or 100 kg/ha with a water table maintained 70 cm below the soil surface. Average results/plant after 13 weeks at low and high N were: DM yield of tops 5.0 and 14.6 g, water consumption 2660 and 4850 cm2, DM yield of roots 1.4 and 3.4 g, total length of all primary roots 2589 and 3374 cm, number of primary roots 103 and 161, number of secondary roots in topsoil 63 and 83 and in subsoil 71 and 83, and total root surface area 1084 and 1736 cm2. ADDITIONAL ABSTRACT: L. multiflorum plants were grown on sandy soil in asbestos tubes with an inner diameter of 15 cm, and 75 cm high, and supplied with 25, 50 or 100 kg N/ha. The soil water level was maintained at 70 cm below soil level. Top growth 8 and 13 weeks after sowing was progressively enhanced by the 2 higher rates, weight increments amounting to at least 72 and 188 %, respectively. These growth increases were accompanied by augmented water consumption, as well as root growth and numbers. (Abstract retrieved from CAB Abstracts by CABI’s permission

The effect of soil compaction at various depths on root and shoot growth of oats.

The effect of a loose topsoil of 23-63 cm depth overlying a dense subsoil of 35-75 cm depth on root and shoot development was compared with the effect of a homogeneous column of loose soil of 98 cm depth. Shoot weights and, to a large extent root weights, were similar during early growth, but, at later stages, they were higher in the heterogeneous soil columns. Throughout growth, root weights were greater in loose topsoil of the heterogeneous soil columns than in the corresponding layer of the homogeneous columns. Total root weights were higher in the homogeneous columns up to May 23rd, but, at later dates they were higher in the heterogeneous columns. Decreases in root weight at the boundary zone between the layers were mainly due to decreased root branching and, secondarily, to decreased root number. Rooting depth in the dense subsoil increased with increasing thickness of the topsoil, and probably with increasing depth of the water table. Shoot/root ratios at later growth stages were highest for the heterogeneous columns with thin top-soil layers, indicating the presence of favourable growing conditions despite restricted root development. This was confirmed by water consumption data. (Abstract retrieved from CAB Abstracts by CABI’s permission

The developmental pattern of roots and shoots of oats under favourable conditions.

Oats were sown on 24 Mar. in asbestos tubes 75 cm long and 15 cm in diameter filled with humus sand and placed in the open. The water level in the soil profile was maintained at about 70 cm below the soil surface by natural rainfall and by a controlled water supply from shallow dishes in which the tubes stood. Plants were sampled in duplicate at weekly intervals between 13 May and 15 July and the developmental growth pattern of shoots and seminal and nodal roots was examined. The total weight of nodal roots increased until the plant had attained its maximum shoot length, and until about 5 weeks after the last leaf appeared on 26 May. Weights and DM content of the shoots increased over the whole of the experimental period. The greatest number of nodal roots was initiated during 3-10 June, between the end of tillering and the beginning of panicle emergence; after that the numbers initiated per week decreased gradually. The number of seminal roots varied between 4 and 5 per plant and reached their maximum weight just after the end of tillering and before the panicles became visible. After 10 June the weight and growth rate of seminal roots decreased rapidly. Seminal roots and the early initiated nodal roots were the most important part of the root system. In the week before the panicles became visible, root and shoot growth was interrupted; this was thought to be related to the transition from the vegetative to the generative stage. CMC. (Abstract retrieved from CAB Abstracts by CABI’s permission

Onderzoek naar de oorzaken van de slechte bespeelbaarheid van enkele sportvelden in Den Haag

De dienst gemeente-plantsoenen van 's-Gravenhage heeft verzocht aandacht te besteden aan de slechte bespeelbaarheid van verscheidene van hun sportvelden (voetbal en hockey). Het probleem is , dat in natte perioden in herfst en winter te lang water op het veld blijft staan of de toplaag van het terrein te zacht wordt, waardoor het sportveld te vaak voor wedstrijden moet worden afgekeurd. Ook een te gladde toplaag wordt vaak, vooral bij hockey, als minder gewenst beschouwd. Het verzoek om enig onderzoek hield ook verband met het feit dat men de indruk had, dat het bodemkundige aspect bij aanleg en onderhoud van sportvelden nog een verwaarloosd terrein van onderzoek is