Utilization And Evaluation Of Natural Resources In Different Planting Patterns In Double Planting Areas In The Southern Part Of The North China Plain

At present,the wheat-maize replanting planting pattern is widespread in double cropping areas in the southern part of the North China Plain.But there are some problems,such as soil nutrient imbalance and excessive fertilizer input in some areas,which have been gradually followed with public interests.In order to explore a new planting pattern suitable for the southern part of North China Plain,four common planting patterns in this double cropping area,including wheat-maize,wheat-soybean,wheat-peanut and wheat-sweet potato,were surveyed in this experiment,with investigating the distribution of various natural resources in one year,calculating the utilization efficiency of solar energy,heat energy,water and fertilizer resources,and evaluating the productivity,the productive potential and the value of ecosystem service of different planting patterns.The main conclusions are as follows:The distribution of natural resources during the whole growth periods was different in different planting patterns.Firstly,the light accumulation amounts in wheat-maize,wheat-soybean and wheat-peanut patterns were quite similar to each other,but which in the wheat-sweet potato pattern was the highest in these four patterns,since the intercept rate of photosynthetically active radiation above the plant canopy during the late growth stage of sweet potato was significantly higher than other patterns,although that was the lowest in wheat season due to the late harvest of sweet potato.So the yields of wheat and sweet potato in this pattern were respectively the lowest and the highest in its season.To the utilization efficiency of solar energy,it was the highest in the wheat-sweet potato pattern,and the wheat-maize and wheat peanut patterns behind it.In addition,the soil temperature in wheat season was always the highest in the wheat-sweet potato pattern too,and there was no significant difference of soil temperature among each pattern in the early autumn crops season,but there was higher temperature in the wheat-peanut andwheat-potato models in the late growth stages.Secondly,the changes of utilization efficiency of heat energy and solar energy showed the same trend.That is to say that,among the four planting patterns,the wheat-sweet potato pattern was the most utilized for heat,which followed by the wheat-maize and wheat-peanut patterns,but the wheat-soybean pattern used the least energy.Furthermore,crops water consumption and water use efficiency showed the opposite results,such as the wheat-maize and wheat-sweet potato patterns had lower water consumption and higher water use efficiency,and the wheat-soybean pattern had the highest water consumption and the lowest water use efficiency.At last,the fertilizer use efficiency was the highest in wheat-sweet potato pattern,followed by wheat-maize model,which the wheat-soybean pattern was the lowest.In general,among the four cropping patterns,it were showed the highest utilization efficiency of solar energy,heat energy,water and fertilizer in the wheat-sweet potato pattern,followed by wheat-maize and wheat peanut patterns,but those was all the lowest in the wheat-soybean pattern.Moreover,the utilization efficiency of natural resources were closely related to crop yields.Then,the crops productivity in different planting patterns were analyzed.It was found that,in the wheat-sweet potato pattern,the annual total yield was the highest and the total straw output was the lowest,but the net output value and the ratio of output to input were the lowest because it had the highest investment and the cheaper selling price.Comparatively,in the wheat-maize pattern,the annual total yield of crops ranked second,with the lower total straw production but the highest net output value and the highest ratio of output to input due to the lower input and the higher cost in market.And in the wheat-soybean pattern,the net output value and the ratio of output to input was higher,with the lowest annual total yield of the crops,the higher total straw production and the lowest cost.On the other hand,the results of estimating the production potential in different planting patterns showed that the potential forland production in wheat-peanut model was the highest,which followed by wheat-soybean and wheat-maize models,but that was the lowest in the wheat-sweet potato model.Furthermore,ecosystem service value evaluation of the four planting patterns were assessed that,in terms of direct value,wheat-peanut and wheat-maize patterns showed the higher agricultural economic benefits.and the wheat-soybean pattern had a higher economic benefit too because of the highest market price although the lowest crop yield.For the indirect value of farmland ecosystem service value in different planting patterns,wheat-maize,wheat-soybean and wheat-peanut patterns all showed high functional values of accumulated organic matter,water conservation and climate regulation so that they did not only accumulate more organic matter for the soil,but also play an important role in maintaining water and soil and regulating the climate.However,the economic benefits and the ability to maintain sustainable development were the lowest in the ecosystem of the wheat-sweet potato pattern.In summary,among the four planting patterns,the wheat-maize one may be a suitable planting pattern in double cropping areas in the southern part of the North China Plain,not only on account of the higher utilization efficiency of natural resources and economic benefits,but also because of increasing soil nutrient content and water-holding capacity,and regulating farmland climate.Additionally,both wheat-peanut and wheat-soybean patterns could be the alternative to the wheat-maize pattern in this region with the higher economic benefits and advantages of the sustainable development of farmland ecosystems.