摘要:

The soil fertility of an organic banana planation in Tenerife and its relation to mineral nutrition was studied and compared with the same variables investigated previously in conventional plantations. The pH of the organic banana plantation soils, as well as the levels of available Mg and Na, were similar to those of the conventional banana plantations. On the other hand, the values of organic matter and available P, Ca and K of the organic plantation soils showed averages significantly higher than those of the conventional plantations. As regards mineral nutrition, while the foliar N, K and Mg levels of the organic plantation were similar to those of the conventional plantations, the averages of foliar P, Ca, Fe and Zn were higher in the organic plantation, but the Mn and Cu averages were lower, although they did not fall to deficiency levels.

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755153

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Because soil structure seems to benefit from the period under grass in a normal rotation, it is widely assumed that grass roots are primarily responsible (Strutt, 1970). Due credit is also given to efficient drainage, adequate inputs of organic matter, lime and microbial activity. However, it is not clear whether the earthworm is a passive exploiter or a causal agent of structure improvement.

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755154

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

During a three month experiment, water extracts of dried ground leaves ofE. citriodorawere tested at three dilutions for phytotoxic effects on growth and yield ofC. annumL. (Pepper). The results showed that the higher the concentration of the extract, the greater the degree of inhibition on growth and yield. Although plants in all treatments started flowering the same week, in those treated with the highest concentrations of the extract fruit formation lagged behind that of the control for two weeks; while others were delayed for only one week. The final fruit yield per plant was 52.4%, 27.6% and 18.7% of the control for those treated with 0.2%), 1.5% and 3.0% dilutions of the extract respectively. These findings suggest thatC. annumandE. citriodoramay be incompatible as agrosilvicultural plants.

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755155

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Conventional agriculture has been well served for a hundred years by a specialised system of higher education devoted first, to natural science, and then increasingly to economics and the methods of business management. It was during this period that the traditional art of husbandry was transformed into a modern technological industry whose short-term efficiency has been gained, however, only at the expense of accelerating environmental damage. Moreover, in the Third World, the so-called Green Revolution continues to by-pass many of those in most urgent need.

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755156

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Chinampa agriculture, a variety of raised-field agriculture practised in Mexico for centuries, appears to be highly productive and sustainable. Understanding the effects, mode of action, and potential of aquatically derived mulches, which comprise in part the raised fields, is of practical importance in the design of aquatic and terrestrial sectors of chinampa systems. This study in a reconstructed chinampa in Tabasco, Mexico compares the effects of four mulch treatments(Eichhornia crassipes, Azolla mexicana, Paspalumsp., and an unmulched control), with and without weeding, on the growth and biomass of cowpea (Vigna unguiculata). All three mulches increased cowpea biomass; there was no significant difference among them. With mulch, unweeded plots yielded significantly less crop biomass than weeded plots, whereas in the absence of mulch there was no significant difference between weeded and unweeded treatments. Thus, mulching increased crop biomass, but not by reducing weed interference, and the full benefits of mulch were only available to the crop when weeds were removed. A more apparent weed-control effect of mulch would be expected where soil fertility is higher.

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755157

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755158

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755159

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755160

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755161

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1988.9755152

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor