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Moore et al. 1967 found that P. tuberosa cv. Australian Commercial growing in the CSIRO Ginnaderra Field Station contained in excess of 40 mg of total alkaloids per 100 grams of dry weight (0.04%) while those grown nearby in garden rows without clover or added nitrogen contained only 11 mg per 100 grams dry weight (0.01%). [Similarly high alkaloid levels have been noted in fields enriched by several seasons of clover.] DMT was found to be the predominate alkaloid in this strain

In their experiments to determine the effect of nitrogen levels they grew the plants in perlite for 7 weeks. Nitrogen was provided by watering twice daily with Hoagland's nutrient solution containing 0.05, 0.5 and 5 times the recommended nitrogen and in all cases half the phosphorus.

[Regrowth was taken three weeks after cutting to ground level and commencing nitrogen treatments.]

They found an insignificant difference between low and intermediate nitrogen levels on alkaloid production whereas at the high level they reported a mean average in excess of over 20% increased total alkaloids. This was coupled with an increased dry weight for their sample.

Nitrogen levels increased the weight of dry samples from 28.9 grams per 18 plants at the low level, to 33.8 grams per 18 dry plants at the intermediate nitrogen level, to 36.3 grams dry weight per 18 plants at the highest level they evaluated.

Frelich & Marten also found that ammonium nitrogen fertilizer increases alkaloid levels.

Rendig and associates noted no correlation between alkaloid levels in grasses fertilized with Ammonium sulfate and those in normal pasturage. This may reflect the observation of Moore and coworkers concerning the lack of correlateable effects from normal to moderate levels of fertilization. Other factors may also be at work. Marten noted plants grown on peat soil (low nitrogen) showed less growth but had much higher alkaloid content than plants given a complete fertilizer.

Parmar & Brink 1976: Hay was cut on 23 Aug. and fertilizer applied as indicated.
The following tables show the results of:
Fertilizer applied and the resulting total tryptamine content (as mg/gm dry weight)
Evaluating only the uppermost four blades]

Ammonium sulfate
Applied 28 August
Tranquil, BC

(kgN/ha)		26 Aug	22 Sept	14 Oct
0		172	123	105
0		na	108	77
50		na	112	79
100		na	127	90
200		na	146	105

Ammonium nitrate
Applied 21 June
Pitt Meadow, BC

(kgN/ha)		26 Aug	29 Sept	29 Oct
50		169	124	109
100		174	124	111
200		183	135	110
300		200	142	107

Cynamid.
Applied 21 June
Pitt Meadow, BC

(kgN/ha)		18 Aug	28 Sept	28 Oct
0		168	125	106
50		169	128	104
100		169	129	107
200		171	122	112
300		175	125	108

Ammonium nitrate
Applied 21 June
Pitt Meadow, BC

(kgN/ha)		18 Aug	28 Sept	28 Oct
0		171	131	110
50		179	127	115
100		174	130	113
200		176	131	116
300		196	128	112

Urea
Applied 21 June
Pitt Meadow, BC

(kgN/ha)		18 Aug	28 Sept	28 Oct
0		176	127	111
50		178	126	118
100		179	131	117
200		189	124	109
300		206	132	115

Ammonium sulfate
Applied 21 June
Pitt Meadow, BC

(kgN/ha)		18 Aug	28 Sept	28 Oct
0		171	126	10
50		173	125	111
100		174	127	110
200		192	138	123
300		221	152	133

Sodium nitrate
Applied 21 June
Pitt Meadow, BC

(kgN/ha)		18 Aug	28 Sept	28 Oct
0		174	128	107
50		177	128	111
100		183	130	111
200		172	131	108
300		174	130	112

Summary: Highest levels of alkaloids were observed in the uppermost leaves of plants receiving ammonium sulfate at high rates.

[Generally speaking (at high levels): Ammonium sulfate > Ammonium nitrate » Urea > Cyanamid > Sodium nitrate in terms of benefiting alkaloids production.

Two points to remember: This is only true at high levels of high nitrogen fertilizer; there is minimal benefit if plants are shaded or if a balanced fertilizer if used.]

[Nitrates favor vegetative growth (as does high K levels); Ammonium favors alkaloid production.]

Gallagher 1966 and Frelich & Marten 1972 also reported tryptamine concentrations to be related to both the type and the amount of fertilizer used.


Marten et al. 1974 found significantly higher levels of alkaloid in plants grown in an infertile peat soil than in fertile, mineral rich soil. Addition of a complete fertilizer in some cases decreased the alkaloid levels when compared to sterile peat but their results were conflicting. [Moderate phosphorus levels seemed to show an adverse effect on alkaloid content when coupled with high potassium levels and low nitrogen. The thought was that increased potassium diverted nitrogen from alkaloid production to protein synthesis. Phosphorus supplementation alone showed no consistent effects on alkaloid production (unless a `narrow effective window' was suggested by their data).]

While his data points are limited, they suggest that high nitrogen levels shows better effects in high tryptamine producers than for low tryptamine producers.

He also found, in solution culture (hydroponics), that the nitrogen sources increased the alkaloid levels most when applied at high concentrations but that the effects on the alkaloid levels was affected more by the choice of nitrogen source.


Phalaris arundinacea clones grown in solution culture:

Plants were started in soil and grown for 4 weeks under low nitrogen conditions. After clipping to a uniform stubble they were transferred to the solution culture. Harvest was after 35 days and again after another 28 days. The average of these two figures was used

Marten reported the following rank for effective increase of alkaloid levels.

Ammonium chloride>Urea>Ammonium nitrate>Sodium nitrate


Solution culture used:

Modified Hoaglund's Solution (pH 6.6).

One liter containing:

Ca(H2PO4)2	252 mg
H3BO4	2.9 mg
MgSO4	246 mg
MnCl2	1.8 mg
Fe-chelate (sequestrene)	250 mg
ZnSO4	0.2 mg
CuSO4	0.1 mg
KCl	223 mg
MoSO4	0.03 mg
CaSO4	172 mg

Nitrogen was incorporated as indicated in the account above. Nutrient solution was aerated continuously and changed every 3 days.

From Marten et al. 1974;
P.I.# from Simons & Marten 1971):
Clone numbers are USDA clone numbers.
The PI number (Plant Introduction number) is the accession number and country of origin.

Clone #		P.I.#	Total alkaloid (mean of 2 harvests) as % by dry weight.
	[N as kg/ha]		[56]	[225]		[450]		[675]
	[N as ppm]		[25]	[100]		[300]		[400]
6-6		209979 Siberia	0.12%	0.12%		0.14%		0.16%
14-2		234697 Denmark	0.40%	0.48%		0.52%		0.58%
19-7		235547 Sweden	0.31%	0.36%		0.38%		0.44%

Total alkaloid concentration
(mean of 3 harvests; 30, 75 and 88 days)
as % by dry weight

Clone		Infertile peat soil		Fertile mineral soil
5-1		0.10		0.02
11-4		0.19		0.06
28-4		0.14		0.10

Parmar & Brink found uptake of ammonium ions tends to be greater on glei soils than well drained types

[An unrelated side note: Mullet 1970 determined that application of gibberellic acid increases winter production of Phalaris tuberosa in cool areas and reduces excess spring growth but does so with a reduction of seed production.