摘要:

Wheat [Triticum aestivum(L.)] is the major cereal crop of the Chaouia (dryland) region of Morocco. Efforts for self‐sufficiency in wheat will require improved fertility management on the calcareous soils of this region. This research was undertaken to evaluate the suitability of five soil P extractors for predicting the need for P fertilization on 15 important soils in this region. The Olsen (0.5MNaHCO3), the Soltanpour (1.0MNH4HCO3+ 0.005MDTPA) and their dilution modifications, and CaCl2solution P method were evaluated in laboratory and greenhouse experiments.

ISSN:0010-3624    

DOI:10.1080/00103628909368122

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Dry matter wheat [Triticum aestivum(L.)] yield was dependent (R2= 0.57) on plant P concentration and also related to plant P uptake (R2= 0.78). Plant P uptake equalization, after P fertilization, for the 15 soils in this region of Morocco appear to be a function of differences in plant P concentration. The relative yield when regressed on Olsen extractable P was significantly fitted (R2= 0.86) to the Mitscherlich‐Bray model. Plant P uptake regressed on Olsen P, including all soils, best fit a second degree polynomial (R2= 0.57). Including soil P buffer capacity, organic matter and pH improved this fit to R2= 0.77. Fertilizer P requirements necessary to obtain the Olsen extractable P level for 90% relative yield was lower using the nonlinear estimation than by log transformation. For these soils these differences were small and for practical purposes either method could be used to interpret the P fertilizer requirement directly from Olsen extractable P, depending on the computer and software available

ISSN:0010-3624    

DOI:10.1080/00103628909368123

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Phosphorus fertilizer recommendations were compared by interpretations from P isotherms, Olsen extractable P and the Mitscherlich‐Bray model based on the Olsen method for 15 soils from the Chaouia (dryland) region of Morocco. The P isotherms were fit to straight line and second degree polynomial equations. The P buffer indexes (PBI) derived from the isotherms were not significantly correlated to P buffer capacities as measured by a single P buffer capacity index, but negatively correlated to Olsen P (r = ‐0.63), relative yield (r = ‐0.76) and P uptake (r = ‐0.66). Phosphorus in solution was a quadratic function of P added in 0.01 M CaCl2equilibrium solution. The P fertilizer recommendations to maintain soil solution P concentrations at 0.01, 0.12 and 0.20 mg P L‐1were higher than recommended by direct interpretation of plant response to Olsen extractable P and the quantity based on the Mitscherlich‐Bray model as calculated from Olsen available P values. The P fertilizer recommended to maintain soil solution P of 0.10 mg P L‐1was significantly correlated with Olsen P (r = 0.71) as was that recommended Mitscherlich‐Bray log transformation model (r = 0.81), and nonlinear least square estimation (r = 0.78). Field research will be needed to evaluate if the P fertilizer recommended to maintain this solution P concentration is adequate for maximum economic wheat grain yield under field conditions

ISSN:0010-3624    

DOI:10.1080/00103628909368124

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103628909368111

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor