Newark post., 1922-06-28
SOIL FERTILITY DIS
CUSSED BY DEAN McCUE
(Continued from Page Fourl

acid carriers basic Stag, acid phos-
phate, and bone meal produce much
better yields than bone black or
ground rock phosphate.
"In the majority of the soils of this
State it is all important to maintain
a desirable humus content. Conse-
quently, cover crops and green man.
ure crops are quite commonly used.
For the most part these cover crops
are legumes and thus added to the
total available nitrogen content of
the soil. One of the aims in the use
of green manure is to cut down the
amount of nitrogen usually purchased
in commercial fertilizers. Two phases
of this problem are being studied by
the Department of Agronomy.
81. The effect of various types of
lime upon the decomposition of green
manures. This is laboratory ex-
pertinent and the apparatus used is,
l believe, unique. The decomposition
of the green manure is measured by
the quantity of co. gas liberated from
the soil over a period necessary to
establish equilibrium for all soils and
conditions tested. This work is as
yet incomplete, but present results
show that ultimately all treatments
reach the same rate of decomposition
as measured by co. output. Decom-
position of green manures take place
at a more rapid note with hydrated
lime than with other forms of lime.
2. A similar experiment is being con-
Quoted, using ground limestone of diff
ferent degrees of fineness; while the
experiment is as yet unfinished, the
indications are that ground limestone
of a 100 mesh to the inch degree of
finenss will give approximately the
same rate of decomposition Of green
manure in the soil as does burned
lime. Coarser degrees of fineness are
correspondingly slower in their ac-
ton on decomposition Of green man.
ures.
"The Departments of Chemistry
and Soil Bacteriology are co-operat-t
ing on these green manure and lime
experiments. The Chemistry Depart
ment is determining changes in soil
acidity as measured by hydrogen in
concentrations, and the Department
of Soil Racteriology is ascertaining
changes in soil organisms which may
or may not be beneficial to plant pro-
duction.
"The Department of Chemistry IS
conducting Investigations on the toll
erance of plants to acid conditions.
This work will most likely have an
important bearing upon the efficient
utilization of plant food by the grow
ing plant. Prof. Tarr will later on
in the morning go into details regard
ing this work and I will say no more
about it at this time.
"The horticultural Department has
since 1908 been conducting fertilizer
experiments with peaches and apples.
"The peach work started in 1913.
will later give the results to you IN
more or less detail, as the greater
norton of the orchard has been de-
stroved and the field conditions can
not be observed this afternoon.
ain 1921 a new fertility experiment
was begun with peaches with the OBJ
iect in view of ascertaining II possible
tbe most desirable carrier OF nitrogen
and peach fertilization. The trees
were planted in 1921 and fertilized for
the first time in 1922. There are ~
nlots of twenty trees in each. Inc
entire area, with the exception Oh one
block where COW peas are to be grown
as a cover crop, will be fertilized each
wear with acid phosphate and mur,a'e
Of potash. Nitrogen will be appiieu
each wear at the rate OF 5o IDS. oi
actual nitrogen per acre.
"The various carriers OF nitrogen