Biomass production in barley is determined by the amount of solar radiation absorbed by the foliage (Gallagher & Biscoe, 1978). As incident irradiance per unit area varies little between neighbouring sites and seasons in the cereal growing areas of the U.K. (Monteith, 1978), biomass production will largely be governed by the size of the canopy, the orientation of canopy constituents and the efficiency of conversion of absorbed radiation into dry matter (Green, 1984). Reviewing the literature, Monteith & Elston (1983) have highlighted the constancy of mean seasonal efficiency, concluding that growth is limited by the ability of the stand to absorb radiation.
SUMMARYThe effects of differing soil conditions at two sites on the growth of vining peas are described. The work was carried out over several seasons having contrasting rainfall at the time of crop emergence.Topsoil compaction induced by tractor wheelings reduced plant population and yield of vining peas by up to 70%. On the compacted plots peas were unable to compensate for the low population which was demonstrated by the inclusion of a non‐compacted treatment thinned to the same population as the compacted plots.The severity of compaction was greatest when soil conditions were dry at emergence and least severe when wet. It is suggested that compaction resulted in increased ethylene production in the root and shoot tissues and this may be a causal agent of the observed growth modifications.Recultivation of a compacted seed bed prior to sowing resulted in better establishment and higher yields than with the topsoil compacted but final yields were variable when compared to a ploughed control.Double digging did not increase yield above a ploughed control. In one year a 25% yield reduction was attributed to this treatment. The reasons for the reduction in yield are complex but it is suggested that the causal agent was modfied soil and plant water relations resulting in altered crop physiology.Tramlining the crop reduced yield in one year but when the frequency of wheeling damage is considered they would be unlikely to affect productivity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.