The Status and Challenges of Sustainable Intensification of Rice-Potato Systems in Southern China

Potato is the world's largest non-cereal crop, occupying a position critical for global food security. In China, potato is the fourth largest crop adding to food security and incomes. The large population and unremitting reductions in arable land are the most critical root causes of China's food security problems. Hence, crop yield improvements and strategies to improve land use are at the forefront of solutions to increase China's food security. Maintenance of existing land resources while increasing crop yields, avoiding soil quality degradation and wastage of water are enduring problems that have long attracted widespread attention in many research fields. This article, analyzes and discusses the status and challenges to sustainable intensification of rice-potato rotation in southern China. Three significant findings were obtained in this paper, viz. availability of about 16 million hectares of suitable land for rice-potato intensification in southern China in 2016 are reported, several conservation agricultural practices with varying intensity and higher economic benefits in rice-potato rotation than rice-fallow, which may positively effects the environment. It was concluded that agricultural intensification with potato was an economically viable avenue along with good agricultural practices that minimize adverse environmental effects.

ADAPTIVE RESEARCH ON RICE/POTATO ROTATION MODEL (SRI FOR RICE AND MINIMUM TILLAGE METHOD FOR POTATO) IN PADDY LAND OF PHU BINH DISTRICT, THAI NGUYEN PROVINCE

Mô hình luân canh lúa/khoai tây theo phương pháp làm đất tối thiểu (SRI-GMP) được xây dựng và triển khai tại huyện Phú Bình, tỉnh Thái Nguyên trong giai đoạn 2018 - 2019. Nghiên cứu nhằm so sánh giữa canh tác lúa thông thường (độc canh lúa không áp dụng SRI là đối chứng); độc canh cây lúa có áp dụng SRI; và SRI-GMP. Áp dụng SRI-GPM thúc đẩy cân bằng sinh thái, giảm phát thải khí nhà kính, giúp người dân nâng cao nhận thức về bảo vệ môi trường và ứng phó với biến đổi khí hậu. Năng suất khoai tây đạt 25 tấn/ha làm tăng thu nhập từ 4,9 triệu đồng/ha, 210,5 nghìn đồng/ngày công và 1,09 đồng/đồng vốn đầu tư ở canh tác lúa độc canh thông thường lên 141,3 triệu đồng/ha, 644,4 nghìn đồng/ngày công và 2,75 đồng/đồng đối với vốn đầu tư khi áp dụng SRI-GPM tương ứng. SRI-GPM đã tạo ra sự kết nối hợp tác giữa nông dân, doanh nghiệp, nhà khoa học và chính quyền, tạo cơ hội cho nông dân tham gia vào chuỗi giá trị nâng cao giá trị gia tăng và ổn định kinh tế cho người dân địa phương.

INFLUENCE OF TECHNOLOGICAL PRIOMS OF POTATO ROTATION ON PRODUCT QUALITY

Potatoes are a universal crop, also called "second bread", because the level of consumption of this vegetable in the country is very high. It is, at the same time, a foodstuff, raw material for the processing industry, high quality livestock feed and a source of cash for farms and households. In terms of consumption and geographical spread, potatoes occupy one of the leading positions in the structure of food production in Ukraine. In the Vinnytsia region, the area of potatoes occupies 115-118 thousand hectares and the average yield is 120-130 cts / ha, which is several times less potential of this crop. One of the reasons for the low yield of potatoes is the harmfulness of pests and diseases. The most common diseases of potatoes include blight, which is steadily developing and is able to reduce the yield of tubers, their quality. In Ukraine, crop losses from it account for 16-22%, and in the years of epiphytoties can reach 50%. The evaluation of plant diseases is one of the most important and often the most challenging tasks in the epidemiology of plant diseases. Damage to plants by phytophages and pathogens can very quickly result in complete loss of the crop if there is insufficient crop protection. This article confirms the feasibility and effectiveness of the application of modern-day protector tubers and the use of new generation growth promoters and fungicides during the cultivation of tubers. This article confirms the feasibility and effectiveness of the application of modern-day protector tubers and the use of new generation growth promoters and fungicides during the cultivation of tubers. To obtain a crop of potato varieties Povin 285,7 c/ha, which is 58,2 c/ha more than the control, it is necessary to carry out the cultivation of tubers before disembarking the detergent Emesto quantum 273,5 FS, TN, in the rate of 1.2 l of the preparation per ton of planting material, and a growth promoter of Rostock (3 l/t), as well as spraying during the vegetation of plants with fungicides Antracol 70 WP, RF (1,0 kg/ha), Nativo 75 WG, VG (0,3 kg/ha) , Infinito 687.5 SC, COP (1.0 l/ha) and Rostock Bohr and Rostock Iron (1.5 l/ha). Keywords: potatoes, pathogens, pathogens, fungicides, efficiency.

A Comparative Study of Rotation Patterns on Soil Organic Carbon in China’s Arid and Semi-Arid Regions

The practice of crop rotation can significantly impact carbon sequestration potential. In exploring whether crop rotation has the potential to improve soil carbon sequestration in China’s Loess Plateau, soil organic carbon (SOC), soil water content (SWC), soil bulk density (SBD), and soil pH were compared across the 0–1.0 m soil profile, under four crop rotation patterns: lentil–wheat–maize, wheat–potato–lentil, wheat–maize–potato, and wheat–flax–pea. The lentil–wheat–maize and wheat–maize–potato rotations have been practiced over the past 20 years, while the wheat–potato–lentil and wheat–flax–pea rotations were established in 1978 (~40 year rotations). The results showed that under the 20-year lentil–wheat–maize rotation, SOC was not significantly different to that of the wheat–maize–potato rotation, at 6.81 g kg−1 and 6.91 g kg−1, respectively. However, under the lentil–wheat–maize rotation, SWC (9.81%) and SBD (1.19 Mg m−3) were significantly higher, but soil pH (8.42) was significantly lower than the same metrics under wheat–maize–potato rotation (8.43% and 1.16 Mg m−3, and 8.50, respectively). For the 40-year rotations, SWC (9.19%) and soil pH (8.41) under the wheat–potato–lentil were not significantly different to that of the wheat–flax–pea (8.87%, and 8.40, respectively). SOC (6.06 g kg−1) was significantly lower, but SBD (1.18 Mg m−3) was significantly higher under the wheat–potato–lentil than the wheat–flax–pea (7.29 g kg−1, and 1.15 Mg m−3, respectively) rotations. Soil carbon sequestration for the lentil–wheat–maize and wheat–potato–lentil rotations was co-influenced by SWC, SBD, and soil pH, while for wheat–maize–potato and wheat–flax–pea rotations, it was co-influenced by SWC and soil pH. The economic value of the four studied crops is, in order: potato > maize > wheat > flax. The results of the present study suggest that the lentil–wheat–maize and maize–flax–pea rotations are the most suitable patterns to optimize simultaneous economic and ecological development of the study area.

Soil mineralogy and dynamic pedogenic processes in response to redox cycles due to rice and sweet potato rotation

Effect of long-term wet and dry (redox) cycles attributed to seasonally flooded soils in rotation of rice and upland food crops on soil characteristics is not yet available in modern agriculture. The objective of this study was to assess soil morphological features, mineralogical compositions and dynamic pedogenic processes under rotation of rice and honey-taste sweet potato. Four profiles that experienced redox cycles and one that did not (as a control) were sampled for soil analyses. Results showed that all soil profiles, irrespective of redox cycles, derived from similar parent materials as revealed by the same type of weatherable mineral contents (hornblende, labradorite, hypersthene, and olivine or muscovite), ranging within 27–84%. High proportions of easily weatherable minerals corresponded to the high availability of Ca, Mg, Si, Fe, Mn and Cu nutrients, suggesting the release of nutrient reserves from weatherable minerals. In all soils, the clay fraction contained only the one mineral, halloysite. Long-term redox cycles due to rotation of rice–honey-taste sweet potato resulted in a remarkable pedomorphic feature, i.e. discrete large soft black Mn segregation with the highest accumulation in the middle part of soil profiles. Other pedogenic processes were Ca, Mg, and Si translocation from the upper to lower layers of soil profiles, but Fe was retained in the uppermost two horizons. We proposed a new soil classification ‘Manganic Eutrudept’ as a subgroup category to accommodate the soil property of high soft Mn segregation.

Oilseed radish/black oat subsidiary crops can help regulate plant-parasitic nematodes under non-inversion tillage in an organic wheat-potato rotation

Soil conservation is one of the major challenges for agriculture in the 21st century. For this reason, non-inversion tillage systems including subsidiary crops have become popular over the last three decades in Europe. However, the adoption of new agricultural practices may change the diversity and abundance of certain pests and diseases. For example, plant-parasitic nematodes that are major threats towards cultivated plants may be promoted if good hosts, such as certain subsidiary crops and weeds, occur more frequently. The indigenous plant-parasitic nematode fauna under organic farming systems is already adapted to diverse crop rotations and usually dominated by nematodes with broad host ranges. These may be further enhanced in organic farming systems if non-inversion tillage is introduced, which generally increases the abundance and biomass of certain weeds. We evaluated the early effects of non-inversion tillage and subsidiary crops in an organic wheat-potato rotation on plant-parasitic nematodes in two field experiments in two successive years. The total densities of plant-parasitic nematodes increased from an initial 1260 nematodes (100 ml soil)−1 at the start of the experiment to 1850 and 1700 nematodes (100 ml soil)−1 after wheat under non-inversion and conventional tillage, respectively. Plant-parasitic nematode densities then decreased on average to 1100 and 560 nematodes (100 ml soil)−1 after subsidiary crops and potatoes, respectively. Parasitic nematode densities tended to be higher under non-inversion than conventional tillage, except where oilseed radish and black oats had been used as cover crops. For the latter, no differences between tillage treatments occurred. In the second experiment, about 1700 free-living nematodes (100 ml soil)−1 were found under conventional tillage without mulch while under reduced tillage with mulch their numbers were significantly higher at 3100 nematodes (100 ml soil)−1. We conclude that an appropriate choice of subsidiary crops can be an important management factor for the long term sustainability of non-inversion tillage systems.