Sponsor(s):Chinese Society ofAgriculliiral Engineering
24 issues per year
Current Issue: Issue 21, 2017
Journal official website:http://www.tcsae.org/nygcxben/ch/index.aspx
Transactions of the Chinese Society of Agricultural Engineering, the 1st in Agricultural Engineering, is supervised by China Association for Science and Technology, and sponsored by Chinese Society of Agricultural Engineering. It aims to introduce the latest scientific achievements and developing trends of Agricultural Engineering and provides the academic developments abroad and domestic of the discipline. The scope covers agricultural water-soil engineering, agricultural information and electrical technology, agricultural products processing engineering. The journal is included in EI, JST, Pж(AJ), CA and CSCD.
Transactions of the Chinese Society of Agricultural Engineering,2017,Vol 33,No. 21
Nondestructive testing equipment is important for the detection of seed vigor. However, there are few studies based on nondestructive testing equipment in sweet corn seed vigor. Therefore, developing an effective and reliable system for the detection of seed vigor has a certain practical significance. As a bionic electronic system, electronic nose detects the vigor of seed qualitatively and quantitatively through the analysis of sample volatile gas’ fingerprint information. So it is pretty suitable for sweet corn seed detection, though sweet corn seed’s odor is comprised of complicated compositions and small differences exist among seeds with different vigor, which makes the detection difficult. Given that, in this paper, the authors proposed a monitoring method of sweet corn seed vigor based on electronic nose. Five samples of sweet corn seeds with different vigor (germination rates were 83.3%, 70.8%, 54.2%, 38.4% and 3.8%) were detected by electronic nose. Principal component analysis (PCA) and linear discrimination analysis (LDA) were used to process the data by Winmuster software. The results showed that electronic nose could not distinguish the sweet corns with different seed vigor only by PCA or LDA. Then the authors tried to use support vector machine (SVM) method to detect the seed vigor. The results were pretty good. To further research the feasibility of electronic nose application for testing seed vigor, the authors used loadings analysis to find the most useful sensor array. The loadings analysis of electronic nose sensors indicated that the sensors of W1W, W5S, W1S, W2S, W2W and W3S were found to be more sensitive than other sensors. These sensors might play an important role in the discrimination of samples, which provided a reference for the development of special-purpose sensor systems for sweet corn seed samples in future. According to this result, the authors reckoned the sensor array was composed of W1W, W5S, W1S, W2S, W2W and W3S to be the optimized sensor array. To verify the validity of optimization, the classification model and the regression model which were built by SVM method were used to compare the ability of discrimination and prediction between the data before and after optimization. The results indicated that the sweet corns with different seed vigor were well classified by the optimized array. The accuracy of the training set and prediction set belonging to the classification model based on the whole sensor array by using SVM was 97.10% and 96.67%, respectively, and the time taken by modeling was 30.75 s. However, the accuracy of the training set and prediction set belonging to the classification model based on the optimized sensor array by using SVM was 98.55% and 96.67%, respectively, and the time taken by modeling was 21.81 s. Meanwhile, the result showed that the regression model based on the optimized sensor array [ R2 was 0.984, root mean square error (RMSE) was 3.01%] performed better than that based on the whole sensor array ( R2 = 0.913, RMSE = 8.50%). In addition, there was little difference of prediction parameters between the training set and validation set, which meant that the over-fit phenomenon did not exist and the prediction ability of the optimized sensor array was better than the whole sensor array. As a result, electronic nose technology could be used as a feasible and reliable method for the determination of seed vigor during the storage. The result can provide theoretical reference for rapid detection of seed vigor during grain storage using volatile odor information.
Temporal and spatial distribution characteristics of crop straw nutrient resources and returning to farmland in China
Transactions of the Chinese Society of Agricultural Engineering,2017,Vol 33,No. 21
Crop straw resource in China is plentiful, but in different regions the straw resource capacity, the corresponding nutrient resource capacity and available amount of returning to farmland as well as the changes over time have not been very clear. Based on official statistical data and literature review, this study analyzed the capacity of crop straw, the corresponding nutrient nitrogen (N), phosphorus (P) and potassium (K) and available amount of returning to farmland in different time slots at provincial level, aiming to provide scientific basis and reference for rational utilization of straw nutrient resources and nutrient management under zero growth of chemical fertilizer. The results indicated that the capacity of crop straw and its NPK nutrients increased by 85.77% and 104% from the 1980s to the 2010s, respectively. Among the regions, the increase of crop straw capacity and NPK nutrients in Northwest, Tibet Autonomous Region and Heilongjiang Province was more obvious. The crop straw and its nutrient capacity in North Plain, middle and lower reaches of Yangtze River, the Sichuan Basin and Heilongjiang Province accounted for two-thirds of the total capacity in China. By the 2010s, the total crop straw and its total N, P and K capacity in China had reached 9.01 × 10 8 and 2 485.63 × 10 4 t, respectively, equivalent to per unit area of arable land of 6 665.52 and 183.91 kg/hm 2, 1 601.18 and 56.85 kg/hm 2 more than those in 1980s, respectively. Great variability existed among different regions in the capacity of straw and its nutrients from specific kinds of crops. In the 2010s, the proportions of crop straw and its nutrient capacity from cereal crops accounted for 69.86% and 56.47% of the total capacity in China, respectively, and the highest proportions of cereal crop straw and its nutrient capacity occurred in Northeast region. The capacities of crop straw and nutrient from fruits and vegetables accounted for 9.67% and 21.99% of the total capacity in China, respectively, and the Northeast region had the highest proportions of straw and nutrient capacity of fruit and vegetable. The proportions of straw and nutrients capacity from beans, potatoes, oil crops, cotton and other fiber crops were relatively small. The amount of direct straw returning to farmland had continually increased from the 1980s to the 2010s, while the amount of straw returning to farmland after burning increased from the 1980s to the 2000s, and decreased in the 2010s. However, the total amount of straw NPK nutrients returning to farmland increased continually from the 1980s to the 2010s. The total NPK nutrients increased from 583.92 × 10 4 t (N 97.81 × 10 4 t, P 2O 5 40.10 × 10 4 t and K 2O 446.01 × 10 4 t) in the 1980s to 1 770.66 × 10 4 t (N 574.53 × 10 4 t, P 2O 5 105.53 × 10 4 t and K 2O 1 090.60 × 10 4 t) in the 2010s, equivalent to per unit area of arable land of 60.89 kg/hm 2 (N 10.20 kg/hm 2, P 2O 5 4.18 kg/hm 2, K 2O 46.51 kg/hm 2) in the 1980s to 131.02 kg/hm 2 (N 42.51 kg/hm 2, P 2O 5 7.81 kg/hm 2, K 2O 80.70 kg/hm 2) in the 2010s. The ratio of crop straw NPK nutrients returning to farmland was 47.92%, 56.16%, 60.11% and 71.24%, respectively in the 1980s, 1990s, 2000s and 2010s. From the 1980s to 2000s, the increase of the ratio of crop straw NPK nutrients returning to farmland in Inner Mongolia, Xinjiang and Heilongjiang was obvious, but the total amount of crop straw NPK returning to farmland in the North Plain, the middle and lower reaches of the Yangtze River and the Sichuan Basin accounted for more than two-thirds of total crop straw NPK returning to farmland in China.