1044 
Journal of Agricultural Research 
Vol. V, No. 22 
It is next of importance to see whether this “corrected” yield has 
really obviated any of the difficulties. To test this, use may be made 
of the criterion of soil homogeneity proposed by Harris (6). This can 
best be tested upon such data as those furnished by the experimental 
fields of Montgomery (n) or Mercer and Hall (9). 
Figure 2 is a diagram taken from Montgomery (11). It represents a 
field of Turkey wheat grown in 1908-9. This field was divided into 224 
blocks (each 5.5 feet square), as indicated. The grain from each block 
671 
657 
703 
755 
760 
686 
592 
739 
733 
710 
753 
680 
680 
677 
795 
723 
692 
697 
701 
7 i 4 
703 
66s 
590 
712 
688 
648 
646 
654 
559 
684 
762 
683 
658 
7 i 3 
613 
632 
667 
645 
660 
768 
786 
768 
666 
843 
795 
763 
716 
741 
67a 
746 
604 
583 
603 
626 
652 
734 
734 
698 
550 
809 
767 
763 
67 S 
693 
657 
671 
623 
7 i 5 
543 
613 
640 
798 
759 
764 
995 
793 
936 
755 
792 
83 8 
644 
678 
587 
637 
449 
557 
604 
735 
678 
664 
847 
73 i 
880 
728 
722 
761 
642 
680 
654 
673 
760 
709 
682 
724 
774 
860 
787 
725 
664 
851 
690 
770 
644 
701 
632 
610 
682 
668 
661 
677 
709 
776 
657 
678 
623 
838 
636 
681 
735 
580 
620 
675 
76 s 
742 
7721 
698 
652 
661 
768 
777 
745 
768 
851 
7x9 
744 
608 
605 
620 
695 
708 
758 
658 
594 
584 
646 
738 
711 
762 
804 
665 
575 
598 
705 
642 
704 
643 
650 
572 
752 
740 
863 
680 
722 
723 
703 
756 
613 
654 
720 
619 
695 
640 
666 
563 
726 
696 
776 
672 
719 
747 
688 
734 
727 
633 
615 
685 
662 
639 
657 
608 
620 
624 
745 
764 
703 
752 
788 
682 
773 
696 
638 
670 
632 
644 
680 
607 
602 
588 
666 
764 
708 
784 
781 
668 
572 
373 
560 
645 
692 
644 
632 
574 
606 
648 
806 
791 
629 
650 
679 
588 
664 
500 
622 
682 
715 
699 
70 S 
624 
640 
666 
784 
841 
684 
730 
723 
626 
S80 
425 
732 
730 
706 
732 
736 
655 
673 
793 
765 
576 
609 
568 
728 
620 
641 
504 
771 
732 
694 
754 
776 
672 
673 
776 
70 S 
593 
631 
616 
738 
623 
588 
526 
596 
777 
776 
779 
721 
728 
604 
742 
66 s 
621 
611 
623 
646 
617 
649 
605 
636 
780 
765 
801 
762 
745 
673 
725 
606 
638 
633 
671 
657 
621 
617 
683 
726 
835 
668 
664 
691 
770 
775 
68S 
723 
583 
580 
395 
511 
653 
682 
76 s 
770 
842 
661 
690 
735 
801 
779 
672 
668 
604 
606 
447 
526 
661 
602 
662 
640 
700 
650 
655 
563 
600 
730 
690 
713 
530 
568 
410 
478 
636 
710 
786 
720 
753 
690 
727 
652 
677 
781 
725 
709 
597 
640 
506 
539 
690 
66s 
736 
630 
598 
895 
592 
593 
659 
718 
705 
667 
S8S 
560 
655 
633 
733 
726 
815 
670 
601 
883 
614 
633 
686 
718 
688 
608 
602 
582 
704 
644 
736 
609 
706 
790 
678 
695 
715 
622 
658 
597 
632 
713 
585 
657 
495 
6x8 
652 
6S2 
797 
842 
753 
697 
75 ® 
675 
697 
610 
628 
668 
61s 
692 
556 
641 
668 
Fig. 2.—Diagram showing the observed and corrected yield (in grams) of grain on each of Montgomery’s 
wheat plots in 1908-9. The upper figure in each plot is the observed yield and the lower the corrected. 
was threshed and weighed separately. The upper figure in each square 
is the observed yield of grain in grams. The lower figure is the cor¬ 
rected yield obtained by the method outlined above. The mean yield 
of these plots is taken as 68i gm. 
Figure 3 represents the combination plots obtained by grouping the 
plots in figure 2 in groups of four—i. e., a two- by two- fold grouping. 
In this figure the upper number in each plot is the observed yield, the lower 
number the corrected yield, while the middle number is the “calculated" 
yield. This latter is inserted to illustrate the method of obtaining the 
corrected yield. The mean yield of these grouped plots is taken as 
2,723 gm. 
