Sowing date of annual crops in non irrigated condition
To determine the appropriate sowing date of annual crops for green forage and silage in non irrigated condition were conducted the small field trials in Ikhtamir, Arkhangai (high mountain)andBayanchandmaniand Bornuur, Tuv (forest steppe)in 2006-2008.
For field experiments selected 8species (oat, rye, sudan grass, maize,sun flower, rape, pea and soy been) and sown in 4 different date as a June 5, June 15, June 25 and July 5.
In the experiments measured and observed the number of germs, green massat blooming and early seed maturing stages, height and developingstages.
Data was analyzed with SPSS 16.0.
The meteorological data for 2007 and 2008 in high mountain zone shown that, the air temperature for growing season was usually higher comparing with LTA. Unfortunately, in June and Julyof2007 air temperature was higher in 3.6-4.6oCthan LTAand low precipitation. In 2008, the precipitation was lower in 30 mm than LTA.
In forest steppe zone in 2006, the air temperature was lower than LTA, but in 2007 and 2008 was over LTAand low precipitation.
Depending from sowing dates the blooming and early seed maturing dates of annuals different. By 2 years average in non irrigated condition in forest steppe zone the rape, pea and soy bean are able to blooming for all sowing dates from 5 of June to 5 of July. However, rye sown later than 25th June and oat sown later than 15th of June could be bloom in end of August or beginning of September and it would be risky to break by first froze. When sowing from 5 to 15 of June the sun flower, sudan grass and maize can be blooming in end of August and feasible to harvest for green forage.
Sowing later from 25th of June the harvest in early seed maturing stage for most annuals limited.
In high mountain zone also first fall usually in end of August and depending from low temperature in August the annuals impossible to develop to seed maturing stage (Table 1).
Table 1. Blooming and early seed maturing dates
| # | Species name | Blooming | Early seed maturing | ||||||
| 5 June | 15 June | 25 June | 5 July | 5 June | 15 June | 25 June | 5 July | ||
| Forest steppe zone | |||||||||
| 1 | Rape | 15 Jul | 19 Jul | 26 Jul | 15 Aug | 26 Jul | 28 Jul | 5 Aug | 21 Aug |
| 2 | Pea “Vega” | 26 Jul | 3 Aug | 9 Aug | 19 Aug | 5 Aug | 15 Aug | 18 Aug | 29 Aug |
| 3 | Soy bean | 2 Aug | 9 Aug | 15 Aug | 25 Aug | 16 Aug | 24 Aug | 31 Aug | 0 |
| 4 | Rye | 5 Aug | 13 Aug | 19 Aug | 31 Aug | 25 Aug | 30 Aug | 9 Sep | 0 |
| 5 | Oat | 16 Aug | 21 Aug | 27 Aug | 9 Sep | 26 Aug | 29 Aug | 8 Sep | 0 |
| 6 | Sun flower | 16 Aug | 23 Aug | 29 Aug | 4 Sep | 24 Aug | 30 Aug | 8 Sep | 0 |
| 7 | Sudan grass | 17 Aug | 24 Aug | 30 Aug | 14 Sep | 28 Aug | 31 Aug | 10 Sep | 0 |
| 8 | Maize | 19 Aug | 24 Aug | 28 Aug | 3 Sep | 29 Aug | 5 Sep | 0 | 0 |
| High mountain zone | |||||||||
| 1 | Rape | 10 July | 6 Aug | 12 Aug | 20 Aug | – | – | – | – |
| 2 | Rye | 31 July | 18 Aug | 22 Aug | – | – | – | – | – |
| 3 | Oat | 3 Aug | 12 Aug | 24 Aug | – | – | – | – | – |
| 4 | Sudan grass | 5 Aug | 20 Aug | 31 Aug | – | – | – | – | – |
| 5 | Sun flower | 15 Aug | 25 Aug | 30 Aug | – | – | – | – | – |
| 6 | Maize | 16 Aug | 26 Aug | 27 Aug | – | – | – | – | – |