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Effects of farmyard manure compost and biodynamic preparations

Long-term trial at IBDF Darmstadt (since 1980)

since 1992 Winter rye

Third period (research focus: Yield formation and long-term effects)

Variety choice, sowing date, seed density and harvest date of rye in the years 1994-98 (Raupp, 1999)
Year  Yariety
Sowing   Seeds m-2
94 Danko 29.10.93 450 25.07.94
95 Danko 31.10.94 420 26.07.95
96 Danko 21.09.95 270 06.08.96
97 Nomaro 26.09.96 250 29.07.97
98 Amilo 25.09.97 285 27.07.98

The yield level of winter rye in most years was not satisfactory (global mean of the years 1989-91: 27.6 dt ha-1). Therefore, steps were taken to raise yields by cultivating a different variety and by using an earlier sowing date (see table).
This strategy was successful, particularly with the manure treatments (see figure).






Yield WR  
Grain yield of rye in 5 years fertilized with composted manure (CM, CMBD) and mineral fertilizer (MIN) in 3 intensities: low = bottom of the bars, medium = cross line, high = top of the bars (Raupp, 1999)  


Mineral fertilization gave higher rye yields in every year (except for 1996).
However, the yield difference between organic and mineral fertilization was smaller in years with early sowing (1996-98).
Rising fertilizer amounts caused higher yields with both organic and mineral fertilizer.






Ertragskomponenten WR

The development of yield components was controlled by the fertilizer type.

In 4 of the 5 years, the number of ears per m2 was clearly lower in the organic compared to the mineral treatment. The thousand seed weight showed no consistent fertilization effects. In both years with late sowing (1994 and 1995) crop emergence in the manure treatments was lower than in the mineral treatment.

The year 1998 showed peculiarities in some respects. Although crop development and climatic conditions were rather unfavourable, finally an exceptionally high yield of 40.6 dt ha-1 on average was achieved in that year (see figure above). This was the highest rye yield in this trial since 1984. Crop growth started with a very low rate of emergence; in all probability the reason for this was the very dry weather in August and September 97. So there were 17% less plants on the plots compared to the 2 previous years with the same seed density. The number of ears and the thousand seed weight were medium to low. Hence, the number of seeds per ear (not evaluated) may have contributed essentially to the high yield. This parameter is normally well developed by the Amilo variety (cultivated in that year) and was evidently able to compensate for the preceding limitations.









Spearman's rank correlation coefficient for rye yields (Y1) and yield components (Y2) with data of the years 1994-98; Raupp (1999)
Period Parameter Y2 Correlation coefficient rs
94 - 98 growing period
0.437 **
0.427 **
94 + 95 crop density in fall
0.458 *
  ears m-2
  thousand seed weight
0.618 **
0.634 **
0.669 **
96 - 98 crop density in fall
-0.617 **
-0.562 **
  ears m-2
0.466 **
0.407 *
  thousand seed weight
* p<0.05; ** p<0.01

How relevant a yield component is depends upon fertilizer type and sowing date.
Sowing in September effectively led to an extension of the growing period. But only in the manure treatments a significant, positive correlation was calculated between the length of the growing period and yield. The length was of no importance for the minerally fertilized rye.
In the years of late sowing (1994 and 1995), thousand seed weight was a very important yield component for all fertilizer types. When the sowing date was early, yield depended on number of ears; however, this correlation is significant only in the manure treatments.







Correlation coefficient r between nitrogen content in rye straw and the amount of shrunk grain with manure (CM, CMBD) and mineral (MIN) fertilization in 5 years; Raupp (2001)
0.039 0.380 0.627*
1995 -0.140 0.350 0.593*
1996 0.167 0.276 0.114
1997 -0.130 -0.132 0.624*
1998 0.089 0.107 0.805**
* p<0.05; ** p<0.01

Higher levels of mineral fertilizer increased the N content in the straw and the quantity of shrunk grain.
When more mineral fertilizer was applied, both nitrogen contents in the straw and the amount of shrunk grain rose distinctly. This relation did not arise with manure fertilization, as both parameters were not changed by different fertilization levels. This indicates that nitrogen easily available from mineral fertilizer was incorporated mainly into vegetative plant parts and consequently there was an N deficiency during grain filling.
Organic fertilization gave lower N contents in the straw and less shrunk grain than mineral fertilization.







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