Μελέτη φυσιολογικών και αγροκομικών γνωρισμάτων που σχετίζονται με την αύξηση, απόδοση και ποιότητα του ρεβιθιού (Ciser arietinum L.)

The choice of the appropriate sowing date is an important management option to optimize seed yield and quality of chickpea (Cicer arietinum L.) and improve its profitability. The purpose of this study was to investigate, under field conditions, the influence of sowing date on growth, seed yield and quality, ac-cumulation and translocation of dry matter, N, P and K, and on other agronomic and physiological traits of spring sown chickpea. The experiments were con-ducted at the farm of Democritus University of Thrace in Orestiada, in 2 years (2009 and 2010). The soil is silty clay with a pH of 6.68 and 1.01% organic mat-ter. Four chickpea cultivars (Zehavit-27, Andros, Kassos and Serifos) were grown in two sowing dates (March-normal and April-late). The experimental de-sign was a split plot with 4 replications. Sowing date was used as main plots and cultivars as subplots. Plant samples were taken from each plot at all plant growth stages. Dry matter, N, P and K, accumulation seed yield and yield com-ponents, leaf area index, (LAI) chlorophyll content index and nutrient utilization efficiency were determined. Differences in plant growth and development among years and sowing dates were observed. These differences were mainly associated with the corresponding variation in meteorological conditions (rain-fall and temperature). Late sown plants showed lower seed-setting and seed weight, and had lower seed yield, mainly due to the more intense heat and wa-ter stress during anthesis and seed-filling period compared to the normal sown plants. Averaged across cultivars, late sowing reduced grain yield compared to normal sowing by 33% in 2009 (1230 vs. 1840 kg/ha) and 44% in 2010 (1710 vs. 3070 kg/ha). Zehavit-27, Andros and Kassos showed similar seed yield in the early sowing, regardless of weather conditions that prevailed each year. Andros was yielded more in the year with lower rainfall, followed by Serifos, while Zehavit-27 was superior the more rainy year. LAI at the R5 growth stage was positively correlated with seed yield. N, P and K translocation from the vegetative tissues to the seeds was positively correlated with the nutrient ac-cumulation up to the beginning of seed filling (R5), suggesting that it was de-pended on the amount of nutrients that was available for translocation at R5. The N, P and K utilization efficiency for seed production was positively corre-lated with NHI, PHI and KHI, respectively. High N accumulation (>119,8 kg/ha) in the above-ground plant parts at R5, and low seed N content (11,98 kg/στρ.) στο υπέργειο τμήμα των φυτών στο στάδιο R5 και χαμηλή συσσώρευση Ν (<9,58 kg/στρ.) στους σπόρους στην ωρίμανση συνέβαλαν σε απώλειες Ν από το υπέργειο τμήμα των φυτών, οι οποίες κυμάνθηκαν από 0,29 kg/στρ. έως 4,04 kg/στρ. Τα αποτελέσματα έδειξαν ότι η εισαγωγή του ρεβιθιού ως ανοιξιάτικη καλλιέργεια στο σύστημα αμειψισποράς των χειμερινών σιτηρών πέρα από τις όποιες ευεργετικές επιδράσεις της αμειψισποράς (rotational ef-fects), επέστρεψε στο έδαφος, μέσω των υπολειμμάτων των φυτών που πα-ρέμειναν στον αγρό, 0,36-4,6 kg Ν/στρ., ανάλογα με το έτος καλλιέργειας, την ημερομηνία σποράς και την ποικιλία

Growth, grain yield and nitrogen use efficiency of Mediterranean wheat in soils amended with municipal sewage sludge

The application of sewage sludge (SS) to agricultural land can improve soil fertility and physical properties, and enhance crop production. This field study was conducted for two consecutive growing seasons to investigate the influence of SS application on winter wheat growth, grain yield, N accumulation, translocation and use, and on trace elements concentrations in soil and wheat plants under Mediterranean conditions. Treatments consisted of three rates of SS, i.e. 20, 40, and 60 Mg dry weight ha(-1) year(-1), one rate of inorganic fertilizer (IF, 120 kg N ha(-1) year(-1) plus 80 kg P2O5 ha(-1) year(-1)), and an unamended control. The application of SS resulted in tall plants with high early dry matter and N accumulation similar to or significantly higher than those obtained with IF. The lowest SS application rate resulted in grain yield similar to that obtained with IF. Nitrogen use efficiency (NUE) in SS treatments was mainly determined by uptake efficiency, which decreased with increasing SS application rate. Values of NUE and biomass production efficiency with the lowest SS rate were similar to those obtained with IF. SS application resulted in increased concentrations of total and DTPA-extractable trace elements in the soil after the first year, but concentrations were much lower than the regulation limits. Concentrations of Cu, Mn and Zn in wheat plants did not exceed those obtained with IF. Overall, SS could be considered for use as a fertilizer in wheat production systems in the area, serving also as an alternative method of SS disposal