A, harvest time

Generally should be harvested in time when 70% ~ 80% of the pods turn brown. The larger area of continuous production field due to differences in soil conditions and management measures, may lead to different areas of seed maturity is not consistent, at this time, should be harvested first maturity of the earlier part of the area, to reduce the loss of mature seed drop. Harvesting time should take into account the differences in harvesting methods. When harvesting with combine harvesters with higher operational efficiency, harvesting can be done at the optimal harvesting period; while harvesting with small mowers or manual harvesting, with lower operational efficiency, the harvesting time should be advanced appropriately. Harvest time also needs to take into account meteorological conditions. Rainfall will reduce seed quality and increase the difficulty of harvesting operations, and should be avoided as much as possible during the rainy season. The harvest time can be advanced or pushed back appropriately according to the weather forecast.

Second, harvesting methods

Harvesting alfalfa seed is generally available in combine harvesters, mowers or manual harvesting.

When harvesting with a combine harvester, the plants can be sprayed with desiccant for drying treatment 3 to 5 days before harvesting. The desiccant is a contact rust remover, such as diquat, diuron and linuron. Harvesting should be carried out when there is no dew or fog, clear and dry, so that the seeds are easy to be threshed and harvest losses are reduced. Most of the current domestic combine harvesters are not professional forage seed harvesting machinery, so the relevant parameters should be adjusted appropriately when harvesting alfalfa seeds to reduce losses in the harvesting process.

Three, seed drying

Just harvested seeds must be dried immediately. Should make full use of the better weather conditions for exposure or spreading dry, drying site to cement tanning field is good. Drying seeds should be spread into waves, the thickness of no more than 5 centimeters, and turned at the right time.

If the weather is humid after harvest, special drying equipment should be used for artificial drying, such as fire rolling dryers, drying towers, steam dryers and so on. The drying temperature is kept at 30℃～40℃.

Four, seed cleaning

Use of seed professional forage seed cleaning machine for drying the seed cleaning, to minimize the loss of net seed under the premise of removing the seed in the seed of the mixture or other plant seeds. Commonly used clearing methods are air sieve clearing, specific gravity clearing, nesting clearing and surface characteristics clearing. Commonly used equipment are airflow screening machine, specific gravity cleaning machine, nest eye disk separator and spiral separator.

Five, post-harvest seed field management

After the seed harvest, the field should be cleared of draft stalks in a timely manner. For seed fields with excessive plant density (greater than 25 plants/m2), in-row thinning should be carried out. When the row spacing is 60 cm, the plants within the length of 30 cm in the row should be ploughed out every 30 cm.

According to the soil nutrient status of the seed field, appropriate amount of phosphorus fertilizer, potash and other fertilizers. Before winter, it is necessary to irrigate enough winter water.