Studies On The Effect Of Mixed Controlled-Release Fertilizer In Winter Wheat And Summer Maize Rotation System

The rate of release of nutrition for slow/controlled release fertilizer is lined with crop’sabsorption.And it can significantly increase crop yield and fertilizer utilization rate, reducingnitrogen volatilization and leaching.But the prices of film material used in slow/controlledrelease fertilizer is higher, restricted the promotion of a large area in the field.Controlledrelease fertilizer combined with common uera has the characteristics of slow/controlledrelease fertilizer, meeting crop nutrient demanding for growth and can be used in field in largearea for its simple technology, low cost. The paper selected controlled release urea forexperiment material and combined the methods of the simulation test in the laboratory andfield experiment, so as to study the fertilizers nutrient release characteristics and theirphysicochemical properties in soil.The yields and economic benefits of summer maize andwinte wheat were also studied. And the main findings as follows:1. Controlled release urea nutrient cumulative release amount of parabolic, initialdissolution rate,7d static dissolution rate, cumulative release amount of28d fertilizernutrients, nutrient differential dissolution rate has reached the industry standard.The treatmentwith50%and100%controlled release urea delayed the ammonia volatilization and reducedits ammonia volatilization peak.The treatment with diffetent ratio of controlled released ureareduced the decline the content of soil total nitrogen and available nitrogen.And the trend wassensible increased with the increase of the ratio of controlled release urea. The content of soilnitrate nitrogen and ammonium nitrogen increased with the increase of nitrogen levels andtheir raito of controlled release urea under different treatment when summer maize and winterwheat were growthed; The content of soil ammonium nitrogen was higer than nitrate nitrogenin winter wheat field while those were similar in summer maize field.2.The yields of maize and wheat were most higest with the treatment of50%ratio ofcontrolled release urea in medium nitrogen levels,increasing1217.7kg per ha and754.0kg perha compared to common regional practice separately; The treatment with50%and100%raitoof controlled release urea in medium nitrogen level increased the ears and kernels per ear inwheat.While, The treatment with30%,50%and100%raito of controlled release urea indifferent nitrogen levels increased kernels per row and seed weight in summer maize.3. The activity of net photosynthetic rate, nitrate reductase activity, SOD activity, CATactivity and soluble protein content were declined with the process of growth of summermaize and winter wheat entering reproductive phase.And the activity declined gently in earlybut dropped sharply in later. The treatment of30%,50%and100%ratio of controlled release urea in medium and higer nitrogen level delayde their decline of physiological activity.4. The change trend of dry matter accumulation of seed in summer maize and winterwheat were both showed “s” curve.The seed filling started slowly under treatment with30%,50%and100%ratio of controlled release urea in diffrent nitrogen levels,while theiraccumulate rate were going up in later stage.The treatment with30%,50%and100%ratio ofcontrolled release urea in medium and higer nitrogen level maintained higer accumulation rateof dry matter in all stage.5. The bilmass of maize and wheat were highest in the treatment with50%ratio ofcontrolled release urea in medium nitrogen level,which was similar to the total nitrogenaccumulation in wheat while the maizes’ was the treatment with50%ratio of controlledrelease urea in the same nitrogen level.NHI declined with the increase of nitrogen level,whilethe treatment with50%ratio of controlled release urea in medium nitrogen leve had a higherlevel.6. The treatment with50%and100%ratio of controlled release urea in medium nitrogenleve in maize and wheat had a higher level of nitrogen use efficiency and nitrogen agronomicefficiency,increasing to16.73%,4.87%and11.11%,17.65%,5.63compared commonregional practice separately.7. The economic benefits of maize and wheat were both highest in the treatment with50%ratio of controlled release urea in the same nitrogen level,increasing2587.23yuan and1357.02yuan/ha compared common regional practice respectively.