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Papers by Edgar Ascencio
Agronomía Mesoamericana, 2016
Two field experiments were established in 1988 at Opico Quezaltepeque, El Salvador, on volcanic-a... more Two field experiments were established in 1988 at Opico Quezaltepeque, El Salvador, on volcanic-ash derived soils to evaluate maize and bean grain yield response to applied sulfur, calcium and potasium. Also under evaluation was the effect of burning crop residues (common practice in this area) compared to zero tillage. The common system employed in this region is a maize-bean relay whereby the maize is planted in May and the beans in August. Four cycles of data were obtained at both locations (2 Maize, 2 beans). The treatments consisted of various combinations of ammonium sulfate and urea with and without sulfur, calcium and potasium. Grain yields were higher when ammonium sulfate (100 kg N/ha) was joint band applied with formula (16-20-0, 30 kg P 2 O 5 ha) under zero tillage. When this same treatment was evaluated when residues were burned, grain yields were significantly lower. When comparing ammonium sulfate snd urea jointly applied with phosphorus a possible response to sulfur ...
AGRONOMÍA …, 1991
Page 1. INTRODUCCIÓN En el área de Opico Quezaltepeque, El Salvador, se siembra el maíz (Zea mays... more Page 1. INTRODUCCIÓN En el área de Opico Quezaltepeque, El Salvador, se siembra el maíz (Zea mays L.) predominantemente en terre-nos de ladera donde es común la práctica de la quema de rastrojos del año anterior ...
Agronomía Mesoamericana, 2016
Two field experiments were established in 1988 at Opico Quezaltepeque, El Salvador, on volcanic-a... more Two field experiments were established in 1988 at Opico Quezaltepeque, El Salvador, on volcanic-ash derived soils to evaluate maize and bean grain yield response to applied sulfur, calcium and potasium. Also under evaluation was the effect of burning crop residues (common practice in this area) compared to zero tillage. The common system employed in this region is a maize-bean relay whereby the maize is planted in May and the beans in August. Four cycles of data were obtained at both locations (2 Maize, 2 beans). The treatments consisted of various combinations of ammonium sulfate and urea with and without sulfur, calcium and potasium. Grain yields were higher when ammonium sulfate (100 kg N/ha) was joint band applied with formula (16-20-0, 30 kg P 2 O 5 ha) under zero tillage. When this same treatment was evaluated when residues were burned, grain yields were significantly lower. When comparing ammonium sulfate snd urea jointly applied with phosphorus a possible response to sulfur ...
AGRONOMÍA …, 1991
Page 1. INTRODUCCIÓN En el área de Opico Quezaltepeque, El Salvador, se siembra el maíz (Zea mays... more Page 1. INTRODUCCIÓN En el área de Opico Quezaltepeque, El Salvador, se siembra el maíz (Zea mays L.) predominantemente en terre-nos de ladera donde es común la práctica de la quema de rastrojos del año anterior ...