Saturday, 15 July 2006

Dynamic and Abailability of Potassium in Soils Andisols and Inceptisols Dedicated to the Potato Cultivation in the Highland Cundiboyacense.

Francisco Jiménez Sr., Monomeros, Calle 77#11-19 piso 9, Cra 25 #139-64 apto 402, Bogotá, Colombia

This investigation was carried out with the purpose of studying the dynamics and availability of potassium in four soils of the municipalities of Toca (Andic Dystrudepts), Siachoque (Typic Dystrudepts), Samaca (Typic Haplustepts) and Villapinzón (Typic Melanudans), located in the highland of Cundinamarca and Boyaca (Colombia) and dedicated to the production of potato (Solanum tuberosum). Physical, chemical and mineralogical characteristics of each one of the soils were evaluated. The different forms of potassium: in solution, interchangeable, not interchangeable, structural and total were determined. The different relations among potassium with the Ca and Mg were carried out and the “index potassium” was determined. In the same way, the capacity of restitution of K was evaluated for each soil, as well as the Buffer capacity (PBCk) according to the methodology of Beckett. (1964). At the same time, the yield and quality response was evaluated with the varieties of potato “parda pastusa” and “diacol capiro” related to the fertilization potasica with three doses (60,120,180 Kg K2O/Ha) and two potassium sources (KCl and SOP) in each one of the studied soils. The soil of Samaca presents a bigger quantity of total potassium (21,1 cmol+kg-1), opposite to the other evaluated soils that they showed a very low level of this fraction.(3,3 to 5,97 cmol+Kg-1). The structural K fluctuates among 1,4 cmol+kg-1 in the soil of Siachoque and 15,7 cmol+kg-1 for the soil of Samaca; The non interchangeable K fluctuates among 1,9 cmol+kg-1 for the soil of Siachoque and 4,94 cmol+kg-1 for the soil of Samaca; the interchangeable K presents values among 0,21 cmol+kg-1 for the soil of Toca and 0,57 cmol+kg-1 in the soil of Villapinzón. The K in solution L-1 fluctuates among 0,03 mmol for the soil of Toca and 0,09 mmol L-1 for the soil of Villapinzón. The mineralogical analysis of the fraction clay reveals that in the soil of Toca and Siachoque is dominated by Kaolinite; in the soil of Villapinzón it prevails the Kaolinite, the Quartz and non crystalline material; in the soil of Samaca there are bigger presence of Quartz, Kaolinite and Muscovite. The evaluation of restitution of K in the evaluated soils (excepting Samaca) it shows that the capacity to restore K to interchangeables forms declines in a quick way, reflecting the little capacity of the soil to restock the K above the level criticizes for this element in the potato cultivation. As for the answer of the potato production to the treatments with three dose and two sources of K was not significant statistical difference for each one of the evaluated variables of production and industrial quality. However, these soils present a drop reservation of K that diminishes their reservations with intensive crops, draining this element in the soil, being necessary to add fertilizers to maintain the sustainable of the potatoes production.

Back to 3.3A Future Challenges in P Fertilization and the Environment - Poster
Back to WCSS

Back to The 18th World Congress of Soil Science (July 9-15, 2006)