ABSTRACT
Nutritive deficiencies diagnosis in soils under rice monoculture. I. Effects on vegetative and reproductive growth

Carlos Rojas W.1, Ciro Belmar N.2 y Pablo Grau B.2
 
Field experiments (spring 1986) in rice production areas of Talca and Ñuble provinces were stablishedin order to detect rice cultivar responses to different fertilization formulas (FF) subjected to long termcropping.Trials included 4 treatments (cultivars) and 4 subtreatments (FF).In both locations, all cultivars were affected in terms of growth, and also showed a delay in maturitydue to absence of phosphorus (P ≤ 0.05).A reduced panicle dry weight in Ñuble location was observad when potassium and sulphur wereomitted, comparing this treatment with NPKS. Soil potassium in this soil was deficient (39 ppm).In general, in soils submitted to long term monocropping, and high production cultivars, other nutrientsbeside N should be included (P, K and S), according to nutrient availability, in order to obtain asatisfactory growth and maturity.
Key words: rice cultivar response, agronomic factors, deficiency exploration
1Estación Experimental La Platina (INIA), Casilla 439, Correo 3, Santiago, Chile.
2Estación Experimental Quilamapu (INIA), Casilla 426, Chillán, Chile.