Polish water resources depend on precipitations, which are variable in time and space. In dry years the water balance is negative in central parts of Poland but sudden thaws and downfalls may result in periodical water excess and dangerous floods almost in the entire country. The retention capacity of artificial reservoirs in Poland permits to store only 6% of the average annual runoff, which is commonly considered insufficient. Another method to increase retention is soil water con-trol. About fifty percent of soils in Poland consist of light and very light sandy soils with low water capacity. Loams and organogenic soils cover approximately 25% and 8.5% area of the country, re-spectively. Almost half of agricultural lands (48%) have relatively good water conditions, but the rest requires soil water control measures. An increase of the soil water content could be achieved by changes of soil properties, water table control and soil water management. Modernization and recon-struction of drainage and irrigation systems, which were built mainly in the period 1960–1980, is needed.

Tropical regions such as Java, Indonesia, still lack publication of soil water retention (SWR) information, particularly at upper Citarum watershed. The SWR is one of the critical elements in water storage and movement in the soil and very important to solve ecological and environmental problems. However, getting the access requires a lot of laboratory meas-urement that is time-consuming and expensive. Therefore, utilizing pedotransfer functions (PTFs) to estimate the water in the soil is needed. This study aims to define soil properties related to the SWR and to evaluate the performance of existing PTFs in predicting SWR. The study was carried out at agroforestry land system soil at upper Citarum watershed, Indonesia. Ten point and two continuous existing PTFs developed for tropical regions were applied in this study. Pearson's correlation (r), mean error (ME), root mean square error (RMSE), and modelling efficiency (EF) were used for evaluation. Cation exchange capacity (CEC), organic carbon (OC), bulk density (BD), and clay were considered as potential soil properties for soil water retention prediction. The performance of PTFs by MINASNY, HARTEMINK [2011] at matric potential of –10 kPaand BOTULA [2013] at matric potential of –33 kPa and –1500 kPa were recommended for point PTFs, while PTFs by HODNETT, TOMASELLA [2002] was for continuous PTFs in predicting SWR. The accuracy of the point PTFs is almost better than the continuous PTFs in predicting SWR in agroforestry land system soil at upper Citarum watershed, Indonesia.

Estimation and application of water retention curves in heavy soils have own specifics. The reason for these specific properties is the composition of the high clay texture. This is manifested by volume changes of soil depending on moisture. Up to 40% change in the volume compared to the saturated state was recorded in the conditions of the East Slovakian Lowland. The results described in this work are based on research work carried out in the East Slovakian Lowland and represent an analysis of selected 42 samples out of a total of 250 samples in which laboratory measurements of soil water retention curves and volume changes were performed. Selected samples represent the localities Senné and Poľany. Volumetric changes were measured in a laboratory by measuring the dimensions of soil samples. Appropriate changes in the volume of soil samples should be measured when determining moisture retention curves. Neglecting this physical effect leads to a distorted determination of the water retention curves in heavy soils. In the laboratory measurement of water retention curves points, changes in the volume of the sample were measured in the range of 0.24–43.67% depending on the soil moisture potential during drainage. In the case of neglecting the effect of shrinkage during the drainage of samples, a certain error is occurring in the calculation of the volumetric moisture. The range of this error was 1–13% of volumetric moisture.