A regional survey of crop response to sulfur fertilization in the Pampas of Argentina

H.S. STEINBACH; R. ALVAREZ

AGROCHIMICA (PISA)

IST CHIMICA AGRARIA

Lugar: Pisa; Año: 2014

0002-1857

Nitrogen and phosphorus fertilizer have been used since many years in the Pampas but sulfur fertilization is incipient and the response of crops poorly understood. We performed a surface balance which indicated that main input has been atmospheric deposition with a small contribution from fertilizers. Sulfur output was mainly grain harvest. Pampean agroecosystems lost 1.68 Mt of sulfur during 140 years of cultivation. The input/output ratio varied from 2.3 to 0.7 in this period. The metaanalysis of 465 sparse field experiment performed in the region, in which the response of the main crops to sulfur was assessed, showed generalized yield increments. The response could not be predicted using soil sulfate-S content, organic matter level or fertilizer-S rate. Average agronomic efficiencies attained were calculated. Using these efficiencies it was estimated that the widespread adoption of the sulfur fertilization practice would allow increasing pampean grain production by 11% which is profitable for farmers. The probability of positive yield increments due to fertilization ranged from 55 to 75% depending on the crop.