Effects of Reduced Tillage and Fertilization Practices on Soil Characteristics, Plant Water Status, Growth and Yield of Upland Cotton

Abstract

Three different tillage practices, conventional (mouldboard ploughing at 22-25 cm plus one rotary hoeing at 5-6 cm, CT), minimum (one rotary hoeing at 12-15 cm, MT), and no-tillage (direct drilling in soil covered by vetch residues, NT), combined with three fertilization treatments, inorganic (50 kg N ha )1 as ammonium sulphate), cattle manuring (30 t ha )1 ), and control (no-fertilizer), were applied on a cotton crop (Gossypium hirsutum L. cv. Acala SJ-2) grown on a clay loam soil in the field of the Agricultural University of Athens. Soil (gravimetric water content, bulk density, and penetration resistance in the top 40 cm) and plant parameters (root growth, leaf water potential, leaf area growth and seedcotton yield) were recorded throughout the cultivation period in all treatments. No-tillage was associated with significantly higher values of soil water throughout the observation period caused by the vetch mulch. Bulk density and penetration resistance were initially higher in the no-tilled plots, but they became significantly lower after 2-3 months from sowing. These beneficial effects on soil properties favoured root growth, expressed as root surface density, in the NT-plots at the top soil layer. Similar, although less spectacular, effects were observed in the manured plots. Plant water status, expressed in terms of the water potential index, was significantly and consistently best in the NT-and worst in the CT-plots throughout crop growth. In addition, NT favoured a better foliage growth and resulted in significantly higher yields than the other tillage practices. In general, NT, and in second instance, MT considerably improved plant water status, and hence foliage growth and yield in comparison with CT by maintaining higher levels of soil water and improving root growth. Manuring positively interacted with the reduced tillage practices for most soil and plant parameters.

Phenolic compounds of Hibiscus sabdariffa and influence of organic residues on its antioxidant and antitumoral properties

“…The content of phenolic compounds and other phytochemicals present in medicinal plants, as well as in fruits and vegetables, is largely influenced by the type of cultivation, genetic factors, environmental conditions, in addition to the degree of maturation and the variety of the plant (Koleva et al, 2002;Melo et al, 2006). The fact that the highest phenol content was obtained using soil with poultry litter and incorporated organosuper  is due to an improvement in soil physical properties, such as an increased soil water retention (Karamanos et al, 2004); this is in addition to an improvement in the balance of soil nutrients (Blaise, 2006).…”

Conservation Tillage: A Promising Perspective for Sustainable Agriculture in Greece

“…In this experiment, the most energy demanding operation was irrigation, fuel, and electric energy of the pumping system. Karamanos et al (2004) studied the effect of tillage systems on cotton (Gossypium hirsutum L.) growth. Three tillage practices, conventional (mouldboard ploughing plus one rotary hoeing), minimum (one rotary hoeing), and NT (direct drilling in soil covered by vetch residues) were applied on a cotton crop grown on a clay loam soil.…”

Soil Conservation Tillage Effects on Yield and Water Use Efficiency on Irrigated Crops in Central Italy

“…It has been shown that in conservation tillage systems, more water is generally stored in the soil profile compared with conventional systems, due to lower soil evaporation, increased infiltration and soil conductibility, reduced runoff and deep percolation, mainly as a consequence of the presence of crop residues on the soil surface and of soil structure modifications (Blevins et al 1971, Hill and Blevins 1973, Tyler and Overton 1982, Munawar et al 1990, Unger 1990, Blevins and Frye 1993, O'Leary 1996, Hatfield et al 2001, Shukla et al 2003, Karamanos et al 2004. Additionally it has been reported that in conservation tillage, particularly in NT, there is usually a larger presence of biopores than in conventional tillage (CT) (Lo Cascio and Venezia 1986).…”