Effects Of Water And Fertilizer Coupling On Photosynthesis Of Han Yuan Pepper

The study about the effect of different water and fertilizer coupling treatments on the growth and photosynthesis of Hanyuan pepper was carried out by using the Hanyuan pepper as experimental materials and setting different soil moistures and fertilizer rates. By analyzing the influence mechanism of the water and fertilizer coupling effect on Hanyuan pepper, we could conclude the optimal management measures of water and fertilizer for promoting the growth of Hanyuan pepper, which could offer some theoretical basis and technical support for the growth, cultivation and management of Hanyuan pepper. The main results were:(1) Different water and fertilizer coupling treatments had different effects on the growth of pepper. Under the same water moisture treatment, we found that the ground diameter, seeding height of the pepper increased with the increasing of fertilizer rate; Under the same fertilizer treatment, the ground diameter, seeding height of the pepper showed a tendency of firstly increasing and then decreasing with the increasing of soil moisture. Soil moisture had a much more significant effect on pepper growth vigor than fertilizer. Therefore, increasing application of NPK fertilizer under proper soil moisture could be beneficial to the growth of pepper.(2) The photosynthesis characteristics indexes were determined through the study on pot cultivation. The diurnal variation of Pn, Tr and Gs of pepper leaf were single peak curves which was firstly increased and then decreased. The Pn changed with the changing of PAR and TEAMP, and TEMP together with air relative humidity affected the Tr of pepper, while TEMP and Tr both affected the diurnal variation of Gs of pepper leaf. Under FWC50+N150P60K150 treatment, the Pn, Tr and Gs of pepper leaf had the maximum and the corresponding occurrence time of peak value were 12:00am,14:00pm and 12:00am, respectively. And the occurrence time of peak value of Pn was later 2 h compared with other two elements under this treatment. The change curve of Ci of pepper leaf was contrary to the change of Pn, whose minimum value of peak value under all treatments showed in FWC30+N0P0K0 treatment. Vpdl of pepper leaf was also single peak curve whose value was affected by Tr and Gs. The treatment with higher Tr and Gs had the lower Vpdl. The WUE was affected by Pn and Tr, and the maximum value was in FWC30+ N150P60K150 which was appeared at 10:00am.(3) Different water and fertilizer coupling treatments significantly affected the Pn, Tr, Gs and Ci of pepper leaf. The maximum value of Pn, Tr and Gs showed in FWC50+ N150P60K150 treatment, while under FWC70+N0P0K0 treatment Ci had the maximum value. Water and fertilizer coupling also significantly affected the Vpdl and WUE, and the maximum value of WUE was in FWC30+N150P60K150 treatment.(4) Within a proper soil moisture, increasing the rate of nitrogenous fertilizer, phosphatic fertilizer and potash fertilizer could be benefit to the growth and photosynthesis of pepper and increase the production of pepper to some extent. For the purpose of the growth of pepper, we recommend the best combination of water and fertilizer rate was 50% field capacity with 150 kg N·hm-2,60 kg P2O5·hm-2 and 150 kg K2O·hm-2.