Inter-row Tillage Research Articles

Weeds in New Seedings of Alfalfa (Medicago sativa) for Seed Production: Competition and Control

Alfalfa (Medicago sativaL. ‘Vernal′) seeded in April in rows 55 cm apart and kept free of weeds produced 820 kg/ha of seed during the year of seeding. Competition from a dense popualtion (40 plants/m of row) of mixed species of annual weeds reduced the seed yield to 45 kg/ha. Competition from a dense population (55 plants/m of row) of broadleaf weeds, a light population (4 plants/m of row) of broadleaf weeds, or a heavy population (75 culms/m of row) of barnyardgrass [Echinochloa crusgalli(L.) Beauv.] reduced yields to 80, 310, and 160 kg/ha, respectively. A weed management system, consisting of EPTC (S-ethyl dipropylthiocarbamate) or profluralin [N-(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro-N-propyl-p-toluidine] applied at or before planting, 2,4-DB [4-(2,4-dichlorophenoxy) butyric acid] applied postemergence, trifluralin (α,α,α- trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) incorporated with the soil when the alfalfa was 20 cm tall, interrow tillage, and a modest input of hand labor brought the crop to harvest free of weeds, and the yields of alfalfa seed were similar to those from plots kept weed-free by hand labor only. When weeds within the rows were controlled by hand labor only, labor inputs as great as 930 h/ha were required to bring the crop to harvest free of weeds, whereas labor inputs of 7 to 17 h/ha removed all surviving weeds when effective weed management systems had been applied.

Effect of intensity, and width of inter-row tillage on the yield of the potato crop

This work was designed to study the effect of the intensity and width of inter-row tillage on the yield of the potato crop. Soil mulch appeared to have no effect on yield. Inter-row tillage benefited the crop although it restricted the growth of weeds only, and did not create soil mulch. It is not of any value to potato yields to carry on with cultivation more than twice. Narrow inter-row tillage (tines 8 inches from the plant) benefited the yield more than wide inter-row tillage (tines 6 inches from the plant). This held true in Kerr’s Pink, although it does not apply in the case of the Red Skin variety, because the lateral spread of the root system is greater in the case of Kerr’s Pink.

Studies in soil cultivation: IX. The effect of inter-row tillage on the yield of potatoes

The experiments conducted at Ottershaw Park in the years 1937, 1938 and 1939 indicate that for a well-drained sandy loam, under a considerable range of moisture-supply conditions, main-crop potatoes do not respond in the absence of weeds to ridging-up, or to deep or frequent inter-row grubbings, by any increase in yield or in the percentage of ware. The crop showed successful powers of adaptation to a range of contrasting inter-row tillage treatments.The potato crop showed considerable sensitivity to weed competition in the early stages of growth. This indicates that it is of great importance to maintain the crop in a weed-free condition during this early period.Inter-row tillage operations on this type of soil should, therefore, be designed to destroy weeds and to provide moderate cover for the tubers. Intensification of such tillage beyond these limits is not of direct benefit to the plants.No moisture-conservation effect of any importance was produced by a 3 in. soil mulch during dry weather, even when the water-table lay within 4 ft. from the surface.A significant upward movement of water from the water-table to the surface soil was observed, but this was limited to a vertical distance of approximately 4 ft. for the soil type described. Beyond this limit the surface soil was apparently unaffected by the depth of the water-table.These results may not be applicable to heavier soil types. It is probable, however, that they would hold good for most sandy loams.The results indicate the desirability of carrying out further experiments on contrasting British soil types, especially in the important potato-growing areas.