Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
a Image of normal soil extracts and saline-alkali soil extracts liquids after centrifugation at 30,000 rpm for 15 min, and passage through a 0.22-μm filter membrane. b The contents of essential macronutrients N, P and K in the saline-alkali soil extracts compared with normal soil extracts. c The contents of essential micronutrients Fe, Zn and Mn in the saline-alkali soil extracts compared with normal soil extracts. The elements are expressed as milligrams per kilogram
