MIMO Soft-sensor Model of Nutrient Content for Compound Fertil- izer Based on Hybrid Modeling Technique

In compound fertilizer production, several quality variables need to be monitored and controlled simultaneously. It is very diifficult to measure these variables on-line by existing instruments and sensors. So, soft-sensor technique becomes an indispensable method to implement real-time quality control. In this article, a new model of multi-inputs multi-outputs （MIMO） soft-sensor, which is constructed based on hybrid modeling technique, is proposed for these interactional variables. Data-driven modeling method and simplified first principle modelingmethod are combined in this model. Data-driven modeling method based on limited memory partial least squares（LM-PLS） al.gorithm is used to build soft-senor models for some secondary variables.then, the simplified first principle model is used to compute three primary variables on line. The proposed model has been used in practicalprocess; the results indicate that the proposed model is precise and efficient, and it is possible to realize on line quality control for compound fertilizer process.

Application of Secondary Nutrient Fertilizer Produced by Leili Group in Rice in Lichuan City

On basis of tests in regions with different elevations, rice sprayed with secondary nutrient fertilizers （×1 000） produced by Beijing Leili Group would signifi-cantly increase yield and incomes, which can be widely applied in Lichuan City or similar areas. With the fertilizer applied, rice yield can be improved by 292.5-505.5 kg/hm2, with increase of 6.63%-10.92%; farmer’s incomes can be enhanced by 877.5-1 516.5 yuan/hm2, with net income growth of 783-1 422 yuan; output-to-input rate kept in 8.29-15.05. The increased rice yield is mainly contributed by the in-creases of setting percentage and thousand-seed weight, of which the former＇s role is more significant. Hence, the fertilizer can be widely applied in Lichuan and similar regions.

Economic evaluation of agricultural pollution control options for China

Environmental sustainability has become a policy priority in China. In agriculture, China has had major success in rehabilitating desertified lands through programs to convert steeply-sloped cropland to forest and limit grazing on sensitive grasslands. However, little has been done in terms of policies for agricultural nutrient management. Runoff and leaching of nutrients in chemical fertilizers and livestock manure are widely acknowledged as significant problems in China. This paper presents an evaluation of agricultural nonpoint pollution control options for China. Options analyzed include design standards（command ＆ control）, performance standards, and design and performance incentives. Evaluation criteria include economic efficiency and effectiveness, environmental impact and risk, and social criteria such as equity and food security. The evaluation indicates that the best options for China involve subsidies to farmers for changing production practices in order to reduce nonpoint emissions, combined with appropriate farmer education and technical assistance.

Impact Assessment of Oil Spillage on Farmlands of Some Communities in Ilaje Area of Ondo State, Nigeria

This study investigated the impact assessment of oil spillage on farmlands of some communities in Ilaje Area of Ondo state. Three farmlands were considered in the course of this study. Two of the three farmlands were within the Ikorigho and Otumara communities that recently experienced oil spillage and they are about 300 m from each other. While the third farm was within the Igbokoda community which is geographically similar but has not experienced oil spillage, it was used as control. The farmland was delineated at each area by the grid technique and soil samples were collected at 0-20 cm depth of the ground. Some physiochemical properties that reflect soil nutrient content and fertility status （pH, electrical conductivity, moisture content, organic matter, nitrogen, phosphorous and cation exchange capacity （CEC）） were determined using standard methods and results from the three areas were compared. There was a significant decrease in the calcium （Ca）, magnesium （Mg）, potassium （K） and organic matter, as well as a significant increase in the electrical conductivity, moisture content and phosphorous content of the oil-spill affected farmlands at Ikorigho and Otumara when compared with the non-affected farmland at Igbokoda. The acidic nature of the farmlands could not be attributed entirely to the oil spill since the control farmland at Igbokoda was slightly acidic. The results show that oil spillage has adversely affected the nutrient level and fertility status of farmland at Ikorigho and Otumara communities, which needs urgent remediation.

Adopting A.pintoi as Live Mulch for Peach Orchards in China:Benefits of Soil and Water Conservation and Comprehensive Eco-service

Soil erosion occurred in orchards has often attracted extensive attentions from the society with environmental considerations,as orchard is one of major methods of agricultural production in China.In the hilly red soil region of China,many orchards are established on slope lands with a lack of grass covers,leading to severe soil losses.In order to mitigate this common environmental problem and evaluate the efficiency of erosion-control approaches,four treatments were set in field plots in this study,including terraced peach orchard with Arachis pintoi cv.Amarillo as mulch and Paspalum natatu and Digitariasmutsii as hedgerows(TTM),terraced peach orchard without conservation measures(TTW),sloping peach orchard with A.pintoi as mulch and P.natatu and Digitariasmutsii as hedgerows(STM),and sloping peach orchard without conservation measures(STW).The surface runoff,sediment yields and the contents of soil nutrients and organic carbon were monitored in the four treatments and the comprehensive eco-service benefits were further evaluated.The results indicate that available phosphorus(AP),available potassium(AK),total nitrogen(TN) and organic matter(OM) in the soils of the TTM treatments and STM were significantly higher than those of the treatments TTW and STW,suggesting positive effects of the vegetation covers on the soil nutrients.Mean annual surface runoff and coefficient ranged from 0.86 to 34.79 m^3,and 0.007 to 0.282,respectively;the treatment TTM exhibited the best water conservation benefits and the treatment STW was the worst.Soil erosion modulus of the plots were 0-28.76t/hm^2 per year in average,and the treatments TTM and STM reduced significantly soil loss in comparison of the treatments TTW and STW;(d) total organic carbon in the vegetation covers ranged from 130.23 to 195.93 kg per year,and that for TTM and STM treatment significantly higher than TTW and STW treatment;comprehensive eco-service values of the orchards were evaluated considering all the factors including water conservation,soil fertility conservation,CO_2 fixation and O_2 supply,ranging from 563.35 $/y to 765.51 $/y.As expected,the treatments TTM and STM had significantly greater eco-service values than the treatments TTW and STW.In summary,we concluded that terraced orchard with A.pintoi as live mulch plus Paspalum natatu and Digitariasmutsii as hedgerows is a highly sustainable land use practice for the slope lands in red soil hilly region of China.

Impacts of Forest Gaps on Soil Properties After a Severe Ice Storm in a Cunninghamia lanceolata Stand

During January–February 2008, a severe ice storm caused significant damages to forests in southern China, creating canopy gaps and changing soil nutrient availability and enzyme activity. To understand the relationships between gap size, changes in the soil environment and the effects that these changes have on soil processes, we investigated the effects of gap size on soil chemical and biological properties in the forest gaps in a Cunninghamia lanceolata stand in northern Guangdong Province, southern China. Ten naturally created gaps, five large(80–100 m^2) and five small(30–40 m^2), were selected in the stand of C.lanceolata. The large gaps showed a significant increase in light transmission ratio and air and soil temperatures and a decline in soil moisture, organic matter,N and P compared with the small gaps and the adjacent canopy-covered plots in the 0–10 cm soil. The differences in organic matter and nutrient levels found between the large and small gaps and the canopy-covered plots may be related to changes in environmental conditions. This indicated rapid litter decomposition and increased nutrient leaching in the large gaps. Moreover, the lowest levels of catalase, acid phosphatase and urease activities occurred in large gaps because of the decline in their soil fertility. Large forest gaps may have a region of poor fertility, reducing soil nutrient availability and enzyme activity within the C.lanceolata stand.

Soil fertilization does not alter plant architectural effects on arthropod communities

Aims While a growing number of studies have demonstrated the impor-tance of intraspecific differences within plant species on associ-ated arthropod communities,little is known regarding the relative strength of these effects compared to environmental factors.In this study,we examined whether intraspecific plant differences and nutrient fertilization interact to shape the arthropod community of a dominant coastal shrub,Baccharis pilularis(coyote bush).Methods We overlaid a fertilization treatment on a 12-year-old common garden experiment planted with erect and prostrate architectural morphs of Baccharis in california,USA.to collect the associated arthropod community,we vacuum sampled the crown of each Baccharis and identified individuals to species or morphospecies.Important Findings We found that arthropod richness and abundance were 2-to 3-fold greater on prostrate Baccharis than on erect morphs,but observed no main effects of fertilizer addition on the over-all arthropod communities.Predators responded as strongly as herbivores to plant morph,and both were unaffected by nutrient additions.Only the specialist stem galler,Gnorimoschema bac-charisella,showed an interactive response to plant morph and fertilization.Nitrogen,phosphorous and potassium addition had opposite effects on the two morphs,increasing stem gall abun-dance by 50%on prostrate morphs,but reducing galling by 20%on erect morphs.the architectural complexity of prostrate morphs could be the driving mechanism of differences in arthropod assemblages.Overall,our results demonstrate that communitylevel consequences of intraspecific differences in plants are strong,rather than being context dependent,and are generally maintained under different resource environments.the growing number of studies showing strong genotype than nutrient effects on associated arthropod communities suggests that this might be a generalized pattern.