1 Subjects: “...total nitrogen...”

2 Subjects: “...total nitrogen...”

3 Subjects: “...soil total nitrogen...”

4 Subjects: “...total nitrogen...”

5 Subjects: “...soil total nitrogen...”

6 Subjects: “...soil total nitrogen...”

7 Subjects: “...soil total nitrogen concentration...”

8 Subjects: “...total nitrogen...”

9 Subjects: “...total nitrogen...”