Effect Of Fertigation Level And Frequency On Growth And Nutrient Utilization Of Field Cotton

In order to study the influence of fertigation level and frequency on the growth of cotton andthe nutrient utilization in field, the experiments was conducted in XinJiang Academy ofAgricultural and Reclamation Science in2012. The Xinluzao33took as the test material.Fertigation level and frequency were included. Fertigation level have3levels: H was shorted forhigh fertilization（N: P₂O₅: K₂O=350:140:70kg/hm²ï¼‰ï¼ŒM was shorted for Medium fertilization（N: P₂O₅: K₂O=250:100:50kg/hm²ï¼‰, L for low fertilization （N: P₂O₅: K₂O=150:60:30kg/hm²ï¼‰; Fertigation frequency at cotton all growth was also3levels:2,4and8. The biologicalparameters of each treatment were measured and the nutrient utilization, the distribution of soilwater and nitrogen and cotton yield were analyzed carefully. The main results as follows:（1） The cotton leaf area index（LAI） and stem diameter were affected markedly by fertigationlevel and frequency and the interaction of both. The cotton fruit was increased firstly and thendecreased at2frequency and4frequency except8frequency; The fruit branches was increasedcorresponding by the improving of frequency; The cotton shedding ratio has decreasedcorresponding with the increasing of frequency under the same fertigation level. Under the samefertigation frequency, the cotton shedding ratio was increased corresponding with the increasing oflevel.（2） The change of cotton dry matter was accordance with the Logistic equation and appeared“S” curve. The cotton vegetative organs dry matter and reproductive organs dry matter showed thesame as all dry matter. Fertigation level notably effect cotton all dry matter. Bigger increase ratewere the characteristic at medium and high fertigation level. In the low level of fertigation, thespeediness growth stage of8frequency became more longer4and2frequency, but in the mediumand high level, its became shorter respectively and the increase rate was improved.（3） The cotton nitrogen accumulation amount was significant effected at the reproductive ofcotton. At the end of cotton growth, the best of nitrogen accumulation amount are8M and8H,and are higher44.28%and44.64%respectively.The cotton boll weight was increasedcorresponding by the improving of frequency. The cotton boll number per plant was increasedcorresponding under the same of fertigation level and frequency respectively. The seed yield of cotton was affected markedly by fertigation level and frequency respectively, but no affectedmarkedly by the interaction of both. With the increased of fertigation frequency,the seed yield ofcotton was increased at the same of fertigaion level. The partial factor productivity of appliedN（PFP） was decreased with the growth of fertigation level. The cotton nitrogen utilization wasdecreased with the growth of fertigation level. Medium fertilization and8frequncy wasrecommended as the best of fertigation management in xinjiang,according by yield and PFP.（4） Each treatment soil water was decreased as the distance from the source increased inhorizontal. In the vertical depth of soil, the soil water was increased from the ground of soil tounder80cm,but decreased in more80cm soil depth. Each treatment soil nitrogen was increased asthe distance from the source increased in horizontal. In the vertical depth of soil, the soil nitrogenwas increased firstly and then decreased in the some depth. An increasing fertigation level resultedin the greater soil nitrogen concentration in every layer of soil. In the horizontal of soil, the soilnitrogen was no different between different frequency, but8frequency was more smaller than4frequency and2frequency at the soil nitrogen content at the vertical depth of soil.