| Nitrogen is one of the essential nutrients for the growth and development of rice.In order to reveal the effects of nitrogen supply levels on agronomic characteristics and nutrient content distribution of different rice plants,two rice varieties,Huang Huazhan and Jingliangyou 1468,were used as the research objects,and potted experiments were conducted by hydroponics.Under 4 nitrogen supply levels of 0,25,50,75 and 100 mg/L,the three different growth stages of tillering,heading and maturity,the dry matter quality of rice roots,stems and leaves,root morphological characteristics and their rice characteristics were studied.The main results of the differences in the distribution of nutrient content in each organ are as follows:(1)The effect of nitrogen supply on rice at the tillering stage.Nitrogen supply promoted the growth of rice total root length,total root surface area,and total root volume.Huang Huazhan and Jingliangyou 1468 total root length increased by 0.85%~96.24% and23.37%~85.86%,respectively;total root surface area increased by 7.78%~ 205.00% and10.33%~83.62%;total root volume increased by 13.71%~195.00% and 16.38%~85.35%,respectively.Nitrogen supply promoted the accumulation of dry matter and nutrient content in the roots,stems and leaves of the two rice varieties Huang Huazhan and Jingliangyou1468,which showed a trend of first increasing and then decreasing with the increase of nitrogen concentration,and its changing law conformed to the quadratic function relationship.The level of 50 mg/L is the most suitable for rice growth.At this time,the accumulation level of dry matter of the two roots,stems and leaves of Huang Huazhan and Jingliangyou 1468 reach the best,increasing by 175.67%,114.81%;61.01%,60.32%;228.10%,98.93%,respectively.(2)The effect of nitrogen supply on rice at the heading stage.Nitrogen supply promotes the growth of total root length,total root surface area and total root volume at heading stage of rice.Under N2 treatment,the total root length of Huang Huazhan and Jingliangyou 1468 increased by 54.62% and 13.84%;the total root surface area increased by 36.63% and55.76%,and the total root volume increased by 189.58% and 54.17%,respectively.Nitrogen supply promoted the accumulation of dry matter and nutrient content in the roots,stems and leaves of the two rice varieties Huang Huazhan and Jingliangyou 1468.With the increase of nitrogen concentration,they both increased first and then decreased.The change law conforms to the quadratic function relationship.When the level was 50 mg/L,the most suitable rice was Huang Huazhan and Jingliangyou 1468.At this time,the cumulative level of dry matter of the roots,stems and leaves of Huang Huazhan and Jingliangyou 1468 reached the best,increasing 71.51%,90.38%;39.94%,46.53%;104.04%,67.07%,respectively.(3)The effect of nitrogen supply on rice at maturity.Nitrogen supply promotes the growth of total root length,total root surface area and total root volume during rice maturity.Under N2 treatment,the total root length of Huang Huazhan and Jingliangyou 1468 increased by 42.12% and 10.52%;the total root surface area increased by 23.86% and39.45%,and the total root volume increased by 87.94% and 36.36%,respectively.Nitrogen supply promotes the accumulation of dry matter and nutrient content in the organs of the two rice varieties Huang Huazhan and Jingliangyou 1468.The total root length,total root surface area,and total root volume of rice can be used as quadratic functions as the nitrogen concentration increases.description.When the nitrogen supply level was 50 mg/L,the most suitable rice varieties were Huang Huazhan and Jingliangyou 1468.At this time,the cumulative level of dry matter of the two roots,stems and leaves of Huang Huazhan and Jingliangyou 1468 reached the best,increasing by 55.81%,85.46%;47.37%,59.54%;111.24%,85.47%,respectively.(4)When nitrogen supply is in the tillering stage,the dry matter of roots,stems and leaves are in a very significant positive correlation(P<0.01),and they are significantly related to the contents of N,P and K in roots,stems and leaves(P<0.05).Or extremely significant(P<0.01)positive correlation.At the heading stage,the root,stem and leaf dry matter masses are also extremely significantly positively correlated(P<0.01),and they are related to the N in roots,stems and leaves,respectively.The content of P and K showed a significant(P<0.05)or a very significant(P<0.01)positive correlation.At the maturity stage,the total root length was significantly positively correlated with root nitrogen,leaf nitrogen and leaf dry matter(P<0.01);the total root length was significantly positively correlated with other physical and chemical indicators(P<0.05)),which indicates that the root morphology of rice plants,the dry matter quality of roots,stems and leaves and the accumulation of nutrient content have a good synergetic trend. |
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