| The pot experiment was conducted to study the effects of slow-controlled release fertilizers?SCRFs?on dry matter accumulation,NPK absorption and accumulation of potato plant and soil available NPK nutrients etc,in order to clarify the rational dosages of slow-controlled release fertilizers for winter potato,aiming at providing the theoretical support and technical basis for the promotion and application of slow-controlled release fertilizers in winter potato fields.The test set five fertilizer levels,respectively:0.00?CK?,13.33?T1?,17.33?T2?,21.33?T3?,25.33?T4?g·pot-1,which is equivalent to?N?:0,150,195,240,285 kg·hm-2.The main results were as follows:?1?During the whole growth process,the dry matter accumulation of potato tubers and whole plants showed a rising trend.The dry matter accumulation increased with the increase of slow and controlled release fertilizers.T2 treatment was the highest,and over the dosage of T2 treatment the dry matter accumulation dosage decreased.After tuber formation,the distribution ratio of dry matter in the tuber increased continuously,and when it was harvested,the proportion of the distribution was as high as 81%.?2?During the whole growth period,the nitrogen accumulation of the whole plant showed a trend of rising at the beginning and then decreasing,reaching the peak at 75 days after sowing.With the increase of slow and controlled release fertilizers?SCRFs?,the tuber and whole plant nitrogen accumulation increased,but the high level of SCRFs will reduce the amount of nitrogen accumulation.In the 60-90d stage after sowing,the total nitrogen accumulation of T2-T4 treatment was significantly different from that of CK treatment.?3?During the whole growth period,the phosphorus accumulation of the whole plant showed a rising trend,but the increase rate was steady.In the 45-60d stage after sowing,the total phosphorus accumulation in the whole plant increased with the increase of the slow and controlled release fertilizer,but decreased with the increase of the slow and controlled release fertilizer in the middle and late growth stage.After 90 days of sowing,the T2?71.81?was highest in all treatments.T1 followed by CK.In this experiment,the distribution ratio of phosphorus in each organ was generally changed from leaf>stem to tuber at the seedling stage and was always tubers>leaves>stems after tubers formed.After 90 days sowing,the distribution ratio of phosphorus in the tubers was as high as 90%,showing tuber finally became the main storage organ of phosphorus.?4?The results showed that the potassium concentration of potato tubers decreased with the increase of slow and controlled release fertilizer,and T1-T4 treatment was lower than that of CK treatment.During the whole growth period,the potassium accumulation of the whole plant at the beginning rose and then decreased.With the increase of the slow and controlled release fertilizer,the total potassium accumulation in the whole plant increased,but it decreased when the dosage exceeded T2.The distribution of potassium in all organs showed a dynamic process:leaf>stem to leaf>tuber>stem to tuber>leaf>stem.?5?The soil nitrate nitrogen content showed a trend of increase-decrease-elevation.During the whole growth period of the potato,except for 30 days after sowing,the soil nitrate content with T2-T4 treatment was significantly higher than that with CK treatment?p<0.05?.At 90 days after sowing,the nitrate nitrogen contents with each treatment was as follows:T4>T3>T2>T1>CK. |
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