Dissertação
Tempo para a ocorrência da resistência a penetração restritiva ao feijoeiro em solo com diferentes estados de compactação
Fecha
2008-10-30Registro en:
GUBIANI, Paulo Ivonir. Time to ocurr restrictive soil resistance to blackbeans in different soil compaction states. 2008. 110 f. Dissertação (Mestrado em Agronomia) - Universidade Federal de Santa Maria, Santa Maria, 2008.
Autor
Gubiani, Paulo Ivonir
Institución
Resumen
Soil compaction and water availability are related to crop performance. Its
individual effects are very difficult to be measured and, possibly, they have joint
effects in field conditions. In periods of lack of rain the plant water deficit and the soil
resistance to root growth are the main factors associated to crop yield losses. How
they affect the biological processes in commercial crops is understood, however,
when and how intense are questions which are hard to answer. The hypothesis
proposed is that the time to a given stress indicator to reach a restrictive state is a
measure of the state of compaction and is related with plant response. Values of
indicators of penetration resistance, relative leaf hydric potential and relative real
evapotranspiration were measured in different states of compaction, with and without
irrigation, and related to blackbeans growth and yield components. The time for soil
resistance to penetration reaching 2 MPa was different for different levels of
compaction and was directly related to grain yield, confirming the hypothesis of this
work. Blackbeans grain yield was the variable which better pointed out the
compaction effect, whereas leaf area index and plant height, because of its low
association with hydric deficit, had lower sensibility to compaction. There was a
significant association of time to penetration resistance to reach 2 MPa with plant
height and grain yield; however, when plants grew with irrigation in compacted soil,
the later was not felt by plants. On the other hand, when compacted soil was not
irrigated but chiseled, there was grain yield increase similar to what was gained by
irrigation. Thus, the results pointed out that the compaction effects is intensified by
hydric deficit, what in the other hand, without hydric deficit, the compaction may have
low impact on crop production. The analysis of time for penetration resistance
reaching restrictive values may be a promisor strategy and also serve as predictor of
soil compaction effects on crop performance.