Attention factors of inoculation of rhizobium in alfalfa

Although rhizobium inoculation can improve the yield and quality of alfalfa, the method of inoculation directly affects the effect of inoculation, and then affects the growth and yield of alfalfa. Therefore, the following factors must be taken into account when using rhizobium inoculum:

1. Soil conditions.

In an area, if a certain leguminous plant has never been planted or has not been planted for more than 5 years (that is, the so-called new area), it is very difficult to have rhizobium in the soil to match that leguminous plant, so nitrogen-fixing nodules will not be formed in the root of the leguminous plant. Therefore, in order to show the advantage of symbiotic nitrogen fixation, alfalfa must be inoculated with matching rhizobium in the new area. In addition, in sandy or nutrient-poor soil, rhizobium inoculation can also effectively improve the growth of alfalfa and improve soil fertility. On the contrary, in the soil where alfalfa was planted continuously, rhizobium inoculation could increase the yield, but the increase was not significant.

2. The compatibility between rhizobium and alfalfa.

Generally speaking, only inoculation with the rhizobium agent with good matching with this kind of alfalfa can achieve the yield increase, if the matching is poor, the rhizobium agent inoculation will not increase the yield. Generally speaking, if the inoculated alfalfa comes from the United States or Canada, the yield-increasing effect of inoculating imported rhizobium is very obvious, and if it comes from other countries, rigorous field trials are needed to determine.

3. The level of fertilization.

The level of nitrogen application directly affected the nodulation amount of alfalfa. High nitrogen application rate inhibited the formation of rhizobium, while low nitrogen application rate slightly promoted it. Phosphate fertilizer can improve the growth of root system and promote tumor formation. Only by comprehensively considering the above factors and inoculating rhizobia according to the ecological and environmental conditions of the planting area can we improve the yield and quality of alfalfa and make the majority of producers obtain good economic benefits.