Effects Of Potassium Addition On The Growth Characteristics Of Silage Maize And Soil Chemistry In Hetao Area

Potassium,as one of the essential elements for plant growth,has an important effect on crop yield and quality.In the process of cultivation and management of silage maize,potassium fertilizer is also an important management means to improve yield and quality.How to apply potassium scientifically is the key content of cultivation and management of high-yield and high-quality silage maize.Based on this,five potassium fertilizer gradients(0 kg/hm~2,39 kg/hm~2,78 kg/hm~2,117 kg/hm~2,156 kg/hm~2)were set in this paper.The five potassium fertilizer gradients were represented by K1,K2,K3,K4,K5 respectively.Through two consecutive years of tests in 2021 and 2022,The effects of potassium fertilizer on the growth characteristics and stoichiometric characteristics of silage maize were studied in order to provide scientific guidance for high-yield cultivation of silage maize in Bayannur region.The results show that:1 Potassium addition significantly affected the biomass of silage maize in Hetao area.With the increase of K application rate,the maximum aboveground biomass,underground biomass and total biomass of silage maize in 2021 and 2022 appeared under the treatment of planting density of 75,000 plants/hm~2and K application rate of 78 kg/hm~2.The maximum total biomass was 44235.00 kg/hm~2and 31852.50 kg/hm~2,respectively.In 2021and 2022,the maximum plant height was 3.51 m and 3.55 m under the potassium application rate of 117 kg/hm~2,and the maximum stem diameter of silage maize was 28.08mm and 27.15 mm under the potassium application rate of 78 kg/hm~2,respectively.2 Different potassium supply levels had significant effects on the contribution rate of silage corn fruit.With the increase of potassium application rate,the contribution rate of silage corn fruit in 2021 and 2022 showed a trend of first increasing,then decreasing and then increasing,and the maximum value was 55.42%and 52.52%respectively under the treatment of 156 kg/hm~2potassium application rate,which was significantly different from other treatments.There was no significant difference in the contribution rate of other organs in 2021,and there was a significant difference between 2021 and 2022 compared with potassium treatment and no potassium treatment.3 Potassium addition has a significant effect on the stem C content of silage maize,and it reaches the maximum value of 53.88%under the potassium application rate of 117kg/hm~2.It also has a significant effect on the above-ground N content of silage maize,and it reaches the maximum value of 2.08%under the potassium application rate of 156kg/hm~2.It had a certain promoting effect on the content of P in leaves,and reached the maximum value of 2.62%under 78 kg/hm~2potassium application,which had a certain influence on the content of K in all organs of silage maize.Appropriate potassium fertilizer addition can promote the absorption and utilization of N and P in stems,leaves,ears and roots of various organs of silage maize.N/P values of above-ground parts in 2021 and leaves,fruits and ears of silage maize in 2022 are less than 14,which are restricted by N content.4 Potassium addition significantly decreased NDF and ADF of silage maize,and also significantly increased CP.Under the potassium application of 156 kg/hm~2,the NDF and ADF of silage maize reached the lowest value(32.40%,21.54%),and CP reached the highest value(13.02%).Moreover,potassium supplementation also significantly decreased NDF and ADF in silage maize stalk.5 With the increase of potassium application rate,the contribution rate of potassium fertilizer in 2021 and 2022 and the agricultural efficiency of fertilizer in 2021 both increased first and then decreased,and the maximum values were 15.87%and 15.87%,respectively,when the potassium application rate was 78 kg/hm~2.20.59%,225.17 kg/kg;Fertilizer partial productivity in 2021 and 2022 and fertilizer agronomic efficiency in 2022showed a decreasing trend with the increase of potassium application,and the maximum values were 2539.71 kg/kg,2266.06 kg/kg and 263.95 kg/kg,respectively,under the treatment of 39 kg/hm~2potassium application.