Effects Of Different Cassava Bud Directions On Cassava-Peanut Intercropping Systems

Cassava{Manihot esculenta crantz) is a kind of potato crop with high economic value and wide use. Cassava-peanut intercropping systems have already achieved good results in the major cassava production area in China, due to the efficient utilization of resources, and the increasing of yield and economic benefit, which can improve the enthusiasm of farmers, so as to promote the development of cassava industry. Cassava have special distribution characteristic of storage root, and planted in different bud directions would impact its production. In order to explore the effect of bud direction on cassava-peanut intercropping, a field experiment was conducted, cassava cuttings were planted in wide-narrow patterns (peanut intercropped in the wide row, not in the narrow) with different bud direction respectively to the East (E, CK), the South (S), the West (W) and the North (N),4treatments in total. The main results are as follows:1. There was a certain "bias" of root range and crop canopy. In the intergrowth stage, cassava tuberous root grew slantingly to cassava line (narrow line), while pods and canopy of peanut grew slantingly to peanut line. Cassava canopy were in favor of cassava line in intergrowth period, then changed to peanut lines (wide line) after peanut harvest.2. Chlorophyll content and soluble sugar content in leaves were compared between4treatments and the two kind of content showed the similar trend. In cassava leaves the highest results were got in N treatment, and the lowest were in W. Conversely, for peanut, the highest and lowest results were got in W and N treatment, respectively.3. In E and W treatments, the fresh tuber yield, dry matter yield and starch yield of cassava located on the north side of peanut were18.7%-24.5%higher than that of on the south, while the pods yield of peanut located on the south of cassava were6.7%and3.9%higher than that of on the north. In N and S treatments, the fresh tuber yield, dry matter yield and starch yield of cassava located on the west side of peanut were1.0%?15.7%higher than that of on the east, while the pods yield of peanut located on the west of cassava were6.7%and3.9%higher than that of on the east.4. In the survey of distribution characteristic of storage root, the percentage of storage root on the cutting base side of cassava was highest (57.9%-74.6%), on the top and both sides were lower (5.4%-17.1%). The numbers of tubers on both sides of cassava cutting in N and S treatment were almost the same, while in E and W treatment, the number of tubers on the north of the cutting were1.8times of that on the south.5. In the comparison of fresh tuber yield and pod yield and total revenue between4treatments, the results showed, for fresh tuber yield, N> S> E> W, the yields of N were5.4 t/hm2(20.3%) higher than W, for pods yield, W> S> E> N, the yields of W were177.8kg/hm2(19.3%) higher than N; for total revenue of cassava and peanuts, N> S> E> W, that of N was1218.60yuan/hm2(4.5%) higher than W.6. After harvest, the content of available N, P, K, total nitrogen, total phosphorus, total potassium in0-20cm and20-40cm soil all decreased compared to that before planted. E. W treatments exacerbated the available N, P and K consumption2.0%?10.7%more than N and S, while raised the organic matter content and pH.In summary, if considering cassava as the main crops or focusing on the overall revenue of cassava and peanut, we recommend that cassava intercropped with peanut with bud direction to the north, if considering peanut as the main crops, the bud direction to the west.