Abstract: The objective of this work was to evaluate the suitability of carbohydrates and amino compounds in soil and soil organic matter (SOM) fractions to depict the management-induced changes in soil over short-term course. Soil samples were collected from two experimental fields managed according to organic farming regulations and a sequential fractionation procedure was applied to separate the light fraction (LF), particulate organic matter (POM), and mobile humic acid (MHA). Contents of carbohydrates and amino compounds were determined in soil and correspondent SOM fractions. Over a 2-year course, carbohydrate contents decreased in the LF fraction while it increased noticeably in the POM and slightly in the MHA fractions leading into questioning whether decomposing materials get incorporated into older fractions. Amino N content constituted up to 30% of total soil N, with a major contribution of the humic fraction (MHA). Although the LF, POM, and MHA fractions showed the greatest amino N content after the compost-legumes combinations, the carbohydrate and amino N contents in the POM and MHA fractions of the unamended soil increased as large as the corresponding fertilized plots, underlining that conservative soil management results in accumulation of labile forms of soil C and N that consequently might build up soil fertility. The changes after different treatments suggest the suitability of carbohydrates and amino compounds as short-term indicators for soil management.

Abstract: In this study at regional scale, the model DSSAT was applied in order to simulate the cultivation of winter durum wheat and tomato to estimate the green water and the blue water through a dual-step approach (with and without supplemental irrigation). The model simulation covered a period of 30 years in three scenario including a reference period and two future scenarios based on forecasted global average temperature increase of 2 and 5°C. In this paper GW e BW contribution for evapotranspiration requirement is presented and analyzed on a distributed scale related to Puglia region (Southern Italy) characterized by high evaporative demand of the atmosphere. For winter durum wheat the GW component was predominant compared to BW, covering almost 90% of the ETc of WW. Under Baseline scenario the weight of BW was of 11%, slightly increasing in the future scenarios. After considering the probability the climate change determine an increase of irrigation practice for WW from climatic point of view we carried out an example of analysis in order to verify the economical convenience of supplemental irrigation for WW cultivation. The probability that irrigation has a negative or zero income ranged between 55 and 60% and the climate change did not impact the profitability of irrigation for WW as simulated for the economic and agro-pedoclimatic conditions of Puglia region considered in this study.For tomato, in the baseline and future scenarios affected by global warming, the analysis of ET components showed with strong evidence the importance of irrigation that is confirmed as irreplaceable practice for obtaining sustainable yield from productive and economical point of view.GW and BW, both in the case of wheat and tomato, appeared dependent on the spatial and temporal distribution of rainfall during the crop cycle, but also on the hydraulic characteristics of soils corresponding to each calculation unit. No Label