TY  - BOOK
AU  - MacCarthy, Patrick
TI  - Humic substances in soil and crop sciences: : selected readings
U1  - 631.417 
PY  - 1990///
CY  - Madison, Wisconsin
PB  - American Society of Agronomy
KW  - Acido humico
KW  - Humus
KW  - Suelos y cultivos
KW  - Suelos
KW  - Fertilidad
ER  -