ISSN:
1573-5036
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
Summary 1. Gypsum was applied at various levels to a grass-clover association, and its effect noted on the yields and composition of both components. 2. Both clover and grass responded markedly and a three-fold increase in dry matter and a four-fold increase in yield of N were noted. 3. The extra nitrogen in the grass was shown to have been derived almost certainly by underground transference from the clover, the amount involved approximating to the amount of N retained in the aerial part of the clover. 4. Whilst a high proportion of the S applied was recovered at rates up to 50 lb gypsum per acre, a low recovery was obtained from greater applications, and as residual SO4 was very low, it is presumed that SO4 was readily leached during one or two periods of heavy summer rainfall. The ease with which SO4 is lost by leaching may merit attention to forms, times and rates of application of S. 5. Nearly all the S in the clover was organic, whereas a big fraction of the S in the grass was SO4-S. In regions where atmospheric returns of S are small and where no S is being made available from the weathering of S-containing minerals, S must be applied in some form or other to promote optimum N-fixation by legumes as grass may utilise almost all the mineral N and S made available from soil organic matter. 6. Over large areas of the South Island of New Zealand it is doubtful if more than 1 lb S per acre is returned annually from the atmosphere and the application of S is of some considerable importance to promote N-fixation by clovers and hence high production from grass-clover associations.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01666125
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