Effects Of Water And Phosphorus On Root Morphology And Nutrient Uptake Of Different Types Of Crops

Phosphorus plays an important role in agricultural production,But world phosphorus resource reserves are not optimistic,water is one of the irreplaceable conditions for plant survival,and it is both interrelated and restricted with phosphorus.Maize?Zea mays L.?,wheat?Triticum aestivum L.?,common perilla[Perilla frutescens?L.?Britt.var.typica?Makino?Makino],cotton?Gossypium herbaceum L.?,soybean?Glycine max?L.?Merr.?,chickpeas?Cicer arietinum L.?,lentils?Lens culinaris Medic.?,and cole?Brassica campestris L.?are important crops in China.We systematically study the coupling effects of water and phosphorus on them,make full use of water and phosphorus resources,and tap the potential of crop root utilization,has a crucial role.In order to reveal the responses of the eight test plants in this study to different water supply intensities and phosphorus supply levels,such as root morphology and nutrient absorption,to provide a theoretical basis for their water and phosphorus coupling effects,We set four water supply intensity gradients?W1:maximum water holding capacity of 35%,W2:maximum water holding capacity of 55%,W3:maximum water holding capacity of 75%,W4:maximum water holding capacity of 100%,?and three phosphorus concentrations(low phosphorus P1:9.5 mg·kg^-1,Medium P2:100 mg·kg^-1,high phosphorus P3:200 mg·kg^-1)three factors and ninety six treatments were used to study water-phosphorus coupling influences on plants.Pot experiments in greenhouse of potted soil cultivation,the morphology and physiological indicators of eight test crops were measured and analyzed after harvest,and the effects of water and phosphorus on biomass accumulation,root morphology,and nutrient absorption of different types of crops were studied.1.Water supply intensity has a significant limiting effect on plant growth and soil available phosphorus content,especially severe water shortage?W1?,However,excess water supply?W4?also inhibited soil available phosphorus content and some plant growth indicators?such as chlorophyll SPAD,root morphology,nitrogen,phosphorus,potassium nutrient accumulation and absorption rate?in this experiment.Under the three phosphorus supply modes,the aboveground and underground dry matter,total root length,root surface area and volume,phosphorus content and accumulation,and soil available phosphorus content of the eight test plants generally increased first and then decreased with the increase of water supply intensity,biomass,plant height,total root length,root surface area and volume,root growth and elongation rates,and accumulation of phosphorus and potassium all reached minimum values under severe soil water shortage?W1?;2.Phosphorus supply can significantly increase soil available phosphorus content,and can generally promote plant height and robustness,increase chlorophyll SPAD,biomass accumulation,root elongation,root surface area and volume,and increase the content and accumulation of phosphorus and potassium elements,which can significantly reduce plant nitrogen content,accumulation and content of soil pH,but the response of biomass allocation,average root diameter,and nitrogen,uptake rate of nitrogen,phosphorus and potassium to phosphorus supply varies among plant species;3.The relationship between water and phosphorus is very close,and they are both interrelated and restricted in the growth and development of plants,the effect of phosphorus supply on plant growth and development depends largely on the intensity of water supply,plant root morphology is very sensitive to soil water supply intensity,and water supply intensity also has a significant effect on soil available phosphorus content,the content of available phosphorus in the soil increased first and then decreased with the increase of soil water supply intensity,phosphorus supply can effectively alleviate the effects of water stress?especially water shortage?on plants;4.There is a modest range of effects of water and phosphorus on plants,based on the morphological characteristics,root morphology and nitrogen,phosphorus,and potassium nutrient absorption and accumulation of each plant,suitable conditions for maize growth are adequate water supply-medium phosphorus?W3P2?,suitable conditions for wheat growth are slight water shortage-medium phosphorus?W2P2?,suitable conditions for leafof common perilla growth are minor dehydration-high phosphorus?W2P3?,suitable conditions for cotton growth are excess water supply-medium phosphorus?W4P2?,suitable conditions for chickpeas growth are excess water supply-high phosphorus?W4P3?,suitable conditions for soybeans,lentils and cole growth are adequate water supply-high phosphorus?W3P3?.Moderate water and phosphorus supply are beneficial to plant growth.Both water and phosphorus deficits have significant limiting effects on plant growth,and different plants have different tolerances to high water or phosphorus supply.Plants'absorption of phosphorus is limited by water,and their use of water is limited by phosphorus,therefore,within the proper range of plants for water and phosphorus,it can be achieved that phosphorus promotes the absorption of water by plants,and water promotes the absorption of phosphorus by plants.