Study on Growth, Nutrient Absorbtion and Top Dressing Technology of Tomat under Organic Substrate Cultivation
|School||Northwest University of Science and Technology|
|Keywords||organic substrate cultivation top dressing tomato growth and development NPK absorption fertilizer utilization rate|
Organic substrates cultivation is the key research factor and the main direction of the greenhouse production, it is an important means to overcome continuous cropping obstacles and use Non-cultivated land in vegetable facility gardering. By using reasonable substrates formula can be improved the yield and quality of tomato fruit. The agricultural biomass in different areas have different numbers and sources, and also different nutrient content of the matrix, therefore the management technology of organic substrates is very crucial. The experiment was conducted with two different substrates on tomato crop, Formula one: rice husk,corn cob and mushroom residue in the volume proportion of 5:2:3, fertilized with organic fertilizer every 10 days, to investigate the dynamic changes of nutrient absorption of tomato and releasing during the whole growth period under the organic substrate;Formula two: wheat husk and awn, mushroom residue and corn cob in the volume proportion of 5:2:3, fertilized at high(H), moderate(M) or low(L) level and in the frequency once for each fruit cluster(A) or once for alternate fruit cluster(B) , to investigate the growth, fruit yield and quality, nutrient absorption of tomato and the fertilizer utilization rate under the organic substrate.The purpose is to provid technical foundations of nutrient management under organic substrate cultivation. This experiment achieved the following results:(1)The substrate constituted with rice husk, corn cob and mushroom residue with the proportion of 5:2:3, the highest nutrient absorption found was K (7.54g/plant) and the lowest nutrient absorption was P (1.25g/plant). The optimum ratio of N,P,K nutrient absorbtion for plant grown is thought in the ratio of 1:0.24:1.45.(2)The substrate constituted with rice husk, corn cob and mushroom residue with the proportion of 5:2:3, showed the release of available nitrogen and phosphorus was basically in the same trend of stable and flat which meant the substrate could provide the nutrients timely. But the available K decreased sharply in the substrate,especially at the fruit set stage. The biggest release was N (819.3 mg/kg) and the smallest was K (364.5 mg/kg).Under this substrate, certain organic fertilizer can satisfy the need of nitrogen and phosphorus of tomato, but more K should be fertilized to facilitate the formation of yield and quality of tomato. (3)The substrate constituted with wheat husk and awn, mushroom residue and corn cob with the proportion of 5:2:3, through regular and reasonable topdressing fertilizer, the EC values of the substrate can be reduced and stabilized within the appropriate range for tomato growth. The pH values did not change significantly during the cultivation period.(4)The substrate constituted with wheat husk and awn, mushroom residue and corn cob with the proportion of 5:2:3, the growth, fruit yield and quality can be significantly affected by different fertilizing levels and fertilizing frequency. Tomato in the treatments A-L and B-M grew the best. The highest yield was got in the treatment B-M, which was 20.5% higher than the control. The effect of treatment A-L is just next to the treatment B-M and its yield is15.8% higher than the control. Treatment B-L grew the worst among all the treatments. Treatment A-L and B-M had better quality, with the expression of high soluble sugar content, Vc content and moderate sugar acid ratio. Soluble solids and lycopene showed higher in the treatment of A-H and B-H.(5)The substrate constituted with wheat husk and awn, mushroom residue and corn cob with the proportion of 5:2:3, nutrient absorption of tomato and the fertilizer utilization rate can be significantly affected by different fertilizing levels and fertilizing frequency. Tomatoes absorbed N and P in the order as follows: A-H>B-H>A-M>A-L>B-M>B-L>CK, and K was absorbed in the order of B-H>A-M>A-H>A-L>B-M>B-L>CK.The highest fertilizer utilization rate is treatment A-L,and the lowest is treatment A-H, treatment B-M has lower N and P utilization rate but more K utilization rate. So N and P should be fertilized at a low level, and K should be fertilized at moderate level in each fruit cluster.(6)The substrate constituted with wheat husk and awn, mushroom residue and corn cob with the proportion of 5:2:3, the total content of N and P in low fertilizer of tomatoes was significantly lower than high fertilizer. The whole content of K in the fruit in low fertilizer was significantly lower than in the moderate and high fertilizer. Different fertilizing frequency did not affect the content of whole N, whole P and whole K in the roots, stems, leaves and fruits of tomatoes significantly.