| Yellow River irrigation area of middle Gansu Province is one of main processing potato growing regions and is important of seed potatoes breeding base in the Northwest China. non-adequate fertilization, especially long-term overuse of chemical fertilizer, severely leads to the decrease of soil organic matter and deterioration in soil physical and chemical as well as biological properties. Seriously affect the sustainable development of the potato industry in the region.A field experiment was conducted to evaluate the effects of chemical fertilizer partially substituted by organic fertilizers on potato tuber yield and agronomic traits of growing stages,dry matter accumulation, chlorophyll content of Leaf in different growing stages, soil mineral nitrogen content and fertilizer use efficiency. The experiment included 10 treatment were set up, including:T1(CK, No fertilizer);T2(100% Chemical fertilizer);T3(3000kg/hm2 Organic fertilizer+90%Chemical fertilizer);T4(3000kg/hm2 Microbial organic fertilizer+90% Chemical fertilizer);T5(3000kg/hm2 Organic fertilizer+80%Chemical fertilizer);T6(3000kg/hm2 Microbial organic fertilizer+90% Chemical fertilizer);T7(3000kg/hm2 Organic fertilizer+70%Chemical fertilizer);T8(3000kg/hm2 Microbial organic fertilizer+90% Chemical fertilizer);T9(3000kg/hm2 Organic fertilizer);T10(3000kg/hm2 Microbial organic fertilizer). The main results are as follows:1.Treatments of partial replace of fertilizer by organic fertilizer.compared with T2 were increased: 12.6%(T3), 5.5%(T4), 10.9%(T5), 8.1%(T6), 8.9%(T7), 5.9%(T8).T3 production reached 34.05t/hm2, Although single organic fertilizer treatment compared to the control treatment(T1) yield is higher, but significantly lower than T2 processing yield, comprehensive income is not high. This experiment 3000kg/hm2 organic fertilizer to replace 10 to 30 percent of the fertilizer is fully able to reach(more than) a pure application of fertilizer effect.2. From the whole plant dry matter, organic fertilizer to replace part of chemical fertilizer treatments were significantly higher than that of the control treatment(T1) and pure organic fertilizer treatment(T9, T10),which deal with the largest dry T3, T1 treatment increased compared with 36.8 percentage points, The diameter of stem and tuber weight and tuber yield has the extremely significant linear correlation, plant height and branch number were significantly correlated with tuber yield. The increase of production more dependent increase in tuber weight.Plant dry weight, root dry weight and ground stem dry weight showed a significant correlation with the yield of potato.Tubers and roots+stem+leaf dry matter accumulation time to reach equilibrium different, T1 and T2 in the balance period of about 37 days after emergence, T9 in 40 days or so, T3, T5, T7, T6 and T10 in the post-emergence 48 days or so, T4 and T8 in about 50 days after emergence. Organic fertilizer each treatment period compared with the control and balance of pure organic fertilizer slightly delayed.3. In different periods of each treatment’s SPAD value and yield were significantly correlated, SPAD value can be used as an indicator of yield prediction.From tuber formation stage T1 SPAD was significantly lower than other treatments, differences in other treatments were not obvious.August 20 SPAD value reaches a significant correlation with the total nitrogen content of leaves, the correlation coefficient was 0.722. Description SPAD values can be better reflected in leaf nitrogen content.4. Among soil mineral nitrogen content with the overall downward trend in the growth period, in which ammonium between each treatment was not significantly different, and the lower levels. Changes between the various processing ammonium nitrogen content is consistent trend.The 0-60 cm of soil ammonium nitrogen content decreased with soil depth in slow. The 0-60 cm of soil ammonium nitrogen content decreased with soil depth in slow.The overall trend of nitrate content decreased with the depth and the time increasing trend.T1, T9 and T10 are not applying fertilizer, the nitrate content of each layer was significantly lower than that of the treatment of chemical fertilizer.Nmin was significantly positively correlated with the amount of fertilizer, chemical fertilizer can directly influence the soil mineral nitrogen content.5.NPK fertilization accumulated volume was higher than the control treatment, which deal with the accumulation of NPK highest T3, respectively 391.25kg/hm2, 110.98kg/hm2,569.25kg/hm2, T1 is lowest, organic and inorganic fertilizer treatments were higher than T2,T2 was higher than pure organic fertilizer treatment, no significant difference between the two organic fertilizers.Organic fertilizer to replace part of fertilizer can enhance N fertilizer use efficiency, to 3000kg/hm2 ordinary organic fertilizer instead of 20% chemical fertilizer treatment(T5) the highest, increased by 24.8% than T2.T5’s fertilizer agronomy highest efficiency, followed by T8, agronomy phosphate fertilizer use efficiency and with a negative correlation between the ratio, T2 pure fertilizer applied agronomic efficiency minimum.Potassium harvest index showed the presence of tuber of potassium in most of the harvest period of plant, the treatment of T3 maximum,T6 minimum,Agronomy efficiency of organic and inorganic fertilizer for each treatment is higher than that of pure chemical fertilizer treatment, that organic and inorganic fertilizer can increase the yield of potato, K in the test agronomic efficiency between 28.4 ~ 44.7kg/kg, the less the proportion of potash fertilizer agronomy efficiency more. |
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