Rice-rice-potato rotation system
Potato likes to grow in the cool environment. The suitable temperature for potato
development ranges from 15-18 0C.If temperature is higher than 25 0C, potato growth
slows down and even stops. Only if temperature drops down below zero, potato plant
would face freezing damage. Temperature during winter period in south subtropical
and northern tropical region is suitable to grow potato. Rice – rice – potato rotation
system not only can make good use of seasonal resources for more food production.
The use of rice straw as field cover in no-tillage potato or as basal fertilizer in tillage
potato can increase the recycling rate of rice straw to gain more plant nutrient supply
and soil organic matter supply.
3.1 Technique used for rice-rice-potato system

Seed potato preparation: The loam soil or sandy soil with good
irrigation system is suitable for rice – rice – potato system. Potato
variety used should be adapt to the specific local climate and soil
condition. Early maturing and mid-maturing varieties are preferred. The
major varieties used in South China include Favorita, Pacific, Cadinal,
Zhongshu No. 3, and Hezuo No.88 etc. Detoxified seed potato which is
free of virus disease pathogen, is important for high yield. The seed
potato can be cut into pieces with 1 to 2 buds each. The seed potato
pieces can be further disinfected and then incubated for germination.
Seed potato pieces are incubated within moist sand bad. It is suitable to
have 10 cm sand below potato and 10 cm sand above potato. The
moisture content of sand should keep at 60%. When the buds emerge
and reach about 1-2 cm, they are ready to be planted in field.
 Planting: After the harvest of second rice crop in fall, potato can be
planted in field.
For no tillage potato, a ditch system should be dig out to facilitate drainage and
irrigation. Ditch around the field and straight ditches about 1.6-1.8 meter apart
within the field are necessary. Ditch is 20 -30 cm width and 15-20 cm depth.
Then the seed potato pieces can be put on the field surface with row space 30- 40
cm and space within row 20-30 cm. Rice straw with 8 – 10 cm thick is used to
cover the seed potato. The amount of rice straw used is straw from 1 – 2 ha rice
for 1 ha of no tillage potato. Enough amount of straw cover is important to keep
moisture, to keep dark environment for potato root system and to provide nutrient
for potato from the straw decomposition. To put soil to partly cover the straw is
needed to hold the straw in position.
1
Fig. 3.1 The layout of no-tillage potato field after the harvest of the second rice in early November
in Guangxi Region, China (By Luo Shiming)
For tillage potato, plough and harrowing after rice harvest is needed. A raised
bed with 85-90 cm width and 20-25 cm high is prepared with a 20-25 cm ditch
between beds. Before bed preparation, basal fertilizer should be put in the middle
of the bed position. Then seed potato pieces are put on the bed with two rows and
then covered with 5-6 cm soil. The density is 60 thousand to 75 thousand plants
per hectare with row space 30 cm and space within row 25-30 cm. The buds of
seed potato pieces should point upward. Rice straw can be put with the basal
fertilizer together within the bed, or cover the bed after planting. Straw covering
the bed should not be too thick to delay seedling emerging. The amount of straw
use is 0.5 – 1 ha rice straw for 1 ha of tillage potato. If straw is put on the bed,
covering some soil to press rice straw on position is needed.
 Fertilization: The nutrition need for production of potato can
be calculated on the base of 5.5 kg of N, 2.2 kg of P2O5 and11
kg of K2O for 1000 kg of potato. The yield of potato usually is
in the range of 15 ton/ha to 37.5 ton/ha during winter season.
This nutrition can be met by different types of organic fertilizer
such as compost, farmyard manure, plant ash, slurry and liquid
from biogas fermentation. Basal fertilizer should include 60%
nitrogen, 100% phosphorous and 50% potassium needs for the
whole season. The remaining fertilizer can be applied in 3 to 5
times according to the growth situation. Liquid form is
2
preferred for better absorption.
Fig 3.2 The tillage potato in rice field in Huizhou, Guangdong Province, China (By Luo Shiming)



Irrigation: The suitable soil moisture for potato growth ranges
from 60 – 80 % of the maximum water holding capacity. For no
tillage potato, a fast and quick irrigation method is
recommended to avoid excessive standing water. For tillage
potato, irrigation water should keep less than half full of the
ditch. During rainy days, to maintain good drainage system for
no-tillage potato is very important.
Thinning: In case of more than 3 shoots come out from one
seed potato, the redundant seedlings should be removed.
Pest control: The most important methods of disease control
include the use of detoxification seed potato, to avoid excessive
nitrogen application, and good drainage during rainy season.
Other pests can be controlled by integrated pest control
methods.
3
Fig. 3.3 Before potato harvest in tillage potato field. It can be seen that rice straw together with
rice straw within the raised bed (by Luo Shiming).

Harvest: There is no special requirement for potato harvest for tillage potato. For
no-tillage potato, it is very easy. Just take out the rice straw cover, potato will be
exposed and is ready to be picking up. The half decomposed straw and the upper
plant parts of potato can be remained in field as organic fertilizer for early rice
production.
3.2 Typical cases and benefit analysis
A farmer Xu Lianjin in Xinlu Village, Guigang, Guangxi Region rent 33.3 ha of
winter fallow paddy field for no-tillage potato from the winter of 2010 to the spring of
2011. The average potato yield was 45 ton/ha. The highest yield reached 53.5 ton/ha.
The price of potato was 2000 Yuan/ton. Total income per hectare was about 90,000
Yuan. The cost per hectare was about 30,000 Yuan. Net income per hectare reached
about 60,000 Yuan. Total net income was more than one million Yuan. The rice field
no-tillage potato in Guangxi Region reached 70 thousand hectare in 2011. It could
reduce 20-30% of the cost and increased yield by 10 – 40% comparing to tillage
potato. In the double rice region, Guangdong Province, the winter potato reached 5
thousand hectare in 2016.
4
Fig. 3.4 The farmers were harvesting no-tillage potato after rice straw was moved aside in
Wuming County, Guangxi (from Zhao Chunxia, 2012)
A potato experiment was conducted in Guangxi Region (He Xinmin et al., 2011) to
compare with no-tillage potato covered with rice straw (NT), tillage potato with rice
straw inside (TS), tillage potato with black plastic sheet cover (TB) and common
tillage potato (CK). The result showed that the black plastic sheet cover could
increase soil temperature and keep soil moisture, it had the highest yield. However,
the rice straw used in no-tillage or tillage potato could also increase yield significantly.
Considering the ability of recycling rice straw and increasing yield, the NT and TS
method were recommended.
Table 3.1 The comparison of different planting method for winter potato in Guangxi
(He Xinmin et al., 2011)
Treatment
TS
TB
NT
CK
Yield
(kg/ha)
Relative
yield (%)
labor
material
28,401.3a
28,977.5a
25,247.9b
23,406.2b
121.3
123.8
107.8
100.0
7320
8654
6510
9291
5625
5250
5940
5700
Cost (yuan/ha)
Total
income
(Yuan/ha)
Net
income
(Yuan/ha)
Relative
net income
(%)
22721
23182
20198
18725
9776
9278
7748
3734
261.8
248.5
207.5
100.0
Reference
He Xinmin, Tan Guanming, Tang Zhouping, He Huyi, Li Lishu, Wang Hui. Studies on Cultivation
5
Pattern of Straw Wrapping Potato in Winter Planting. China Vegetables. 2011 (2): 78-80.
Wang Jianwu and Cai Kunzeng edited. Structure and Technique of Typical Circulation Agriculture
in the field of the Pearl River Delta.2010. China Environmental Sciences Press. Beijing,
China.
Zhao Chunxia edited. Knowledge and Wisdom for Agricultural Development – 10 year practice of
innovative development of Guangxi agriculture. 2012. Hongqi Press. Beijing, China.
Zhang Mingpei. The industry of tuber crops. 2011. Guangxi People’s Press. Nanning, China.
6