Effects Of Different Combination Of Organic And Iorganic Fertilizers On Winter Wheat Yield And Nitrogen Use Efficiency

Reasonable application of chemical fertilizer combined with organic input could not only sustain the high yield of crops but also improve the soil fertility. Seven treatments were established to study the effect of applying chemical fertilizer combined with manure or straw on wheat population, yield and nitrogen use efficiency. The treatments included(1) CK, no any fertilizer,(2) 100% NPK, 100% nutrients supplied by mineral N, P and K fertilizers,(3)25% M, 25% nutrients supplied by dairy manure + 75% NPK,(4) 50%M, 50% manure + 50%NPK,(5) 75% M, 75% manure + 25% NPK,(6) 100% M, 100% nutrients supplied by dairy manure and(7) SNPK, straw return+100%NPK. Main results obtained were as follows:1) The effect of different treatments on winter wheat population and tiller number of winter wheat showed similar trend. Fertilization significantly increased the spike number and tiller number per plant, especially for 75% M. Additionally, application of chemical fertilizer combined with manure obtained higher wheat population and tiller number per plant,compared to NPK treatment or 100% M treatment.2) The grain yield of winter wheat ranged from 4982 to 7445 kg ha-1. All the fertilization treatment significantly increased the grain yield of winter wheat. The grain yield of 75% M treatment was the highest and significantly higher than other treatments, except for 100% M treatment. In addition, the grain yield of 75% M was increased by 49.4% compared with CK(4982 kg ha-1). Application of chemical fertilizer combined with manure could markedly increased the spike number of winter wheat and applying chemical fertilizer could significantly increase the grain number per spike. However, the 1000-grain weight showed no significant difference between different treatments(except for 100% M).3)The nitrogen partial factor productivity of different treatments range from 21 to 41kg/kg. Compared with application of mineral fertilizer alone, mineral fertilizer combined with manure significantly reduced the nitrogen partial factor productivity. The nitrogen physiological efficiency was 22-35 kg/kg, the nitrogen physiological efficiency of 75% M and SNPK was significantly higher than the other four treatments, and there were no significant difference among the other four treatments. The nitrogen agronomic efficiency was 5.7-11.3kg/kg, the highest one was mineral fertilizer only, and significantly higher than othertreatments, 25%M was the lowest one and significantly lower than other treatments. The nitrogen recovery efficiency was in the range of 20-50%, and the highest one was mineral fertilizer application alone being 50%, and was significantly higher than other treatments; the second highest was SNPK, its nitrogen recovery efficiency was 36% which was significantly higher than manure treatments; among manure treatments, nitrogen recovery efficiency of25%M was higher than other three manure treatments; 50%M, 75%M and 100%M have similar nitrogen recovery efficiency.4) Soil nitrogen balance showed that wheat N uptake was 104.2-186.7 kg/ha during wheat season, N application rate was 165-345 kg/ha, N deficit in CK treatment was 70.2kg/ha, 100%NPK and SNPK showed almost balance for N budget, while N surplus more than150 kg/ha was observed in mineral fertilizer and manure amendment treatments. But N surplus may exist in the form of organic N because nitrate N was quite low in soil profile after wheat harvest.Based above results, compared with control, mineral fertilizer combined with manure significantly increased the yield of wheat, and the wheat yield of 75%M was significantly higher than 100%NPK. Moreover, 75%M and 100%M showed significantly higher physiological efficiency of N than other treatments. However, nitrogen partial factor productivity and nitrogen recovery efficiency were significantly lower under manure amendment than single mineral fertilizer treatment. Because of manure treatments was applied two season nutrients during wheat season, so it will be more reasonable use of crop rotation years or long term to assess the nitrogen use efficiency of mineral fertilizer combined with manure treatments.