Title:	Effect of levels of polymaleic acid on the structural stability of saline soils.
Authors:	LOPES, P. R. C. GISBERT, J. M. SOUZA, L. D. GOMEZ, L. D. ALMEIDA, O. A.
Affiliation:	PAULO ROBERTO COELHO LOPES, CPATSA.
Date Issued:	2002
Citation:	In: INTERNATIONAL CONGRESS MAN AND SOIL AT THE THIRD MILLENIUM, 3., 2000, Valencia. Proceedings... Valencia : Geoforma Ediciones, 2002.
Pages:	p. 1055-1064.
Description:	The effect of levels of polymaleic acid was studied on the structural stability of two saline soils exposed to intensive cultivation. Soil samples with undisturbed structure were collected and placed in containers where levels polymaleic acid (0, 10, 20 and 30L/ha) were applied diluted water, in order to raise the moisture up to field capacity. One week later, controlled drip irrigation was applied using a volume corresponding to the pluviometric precipitation of the areas where the samples were collected. The washed soil samples were taken from the containers with the objective of lowering the moisture and separating the aggregates, considering those which passed through a 4 mm sieve and were retained in a 2 mm sieve. From each soil type, four bags of aggregates weighting 1 kg were taken, received a second application of the same levels of the polymer diluted in the irrigation water, adjusting the moisture of the samples of aggregates to 80% of the field capacity. The plastic bags with the humid samples were weighted and closed to keep the moisture uniform. Three subsamples from each bag were taken every 30 days to determine the weighed mean diameter (WMD) of the aggregates up to 150 days. After washing the soil with distilled water, WMD of the aggregates was reduced in the two soil types, in different proportions. The highest levels caused a lower reduction on the stability grade, showing the role of the polymer on protection of the aggregates against disintegration. After 30 days of the second application of the polymer on washed aggregates, WMD started to increase differently for all the treatments, showing is effect on increasing structural stability of the soils.
Thesagro:	Salinidade Argila Condicionador do Solo Dispersão
NAL Thesaurus:	salinity
Keywords:	Soil conditioner Aggregate Dispersed clay Chemicophysical properties
Type of Material:	Artigo em anais e proceedings
Access:	openAccess
Appears in Collections:	Artigo em anais de congresso (CPATSA)