Yield-compatible salinity level for growing cotton (Gossypium hirsutum L.) under mulched drip irrigation using saline water

Soil conditions affect cotton root distribution and cotton yield under mulched drip irrigation

Spatial distribution and dynamics of cotton fine root under film-mulched drip irrigation

Extensive unofficial planting of Bt cotton expressing Cry1Ac toxin has occured for the past two decades in northwestern China, and no mandatory refuge policy has been adopted. The status of Cry1Ac susceptibility of Helicoverpa armigera in this region has not been routinely monitored, nor has the susceptibility to Cry2Ab cotton which has not been released in China. The susceptibility of H. armigera populations to both toxins was assessed in 2014 and 2015 in two contrasting cotton farming systems across the region. Over the 2 years, the response to Cry1Ac of the nine H. armigera field populations sampled ranged from 3.16 to 16.94 μg ml−1 for LC50 and 0.013 to 0.741 μg ml−1 for IC50, and the baseline susceptibility of these strains to Cry2Ab ranged from 3.43 to 19.05 μg ml−1 for LC50 and 0.16 to 3.81 μg ml−1 for IC50. There was no significant difference in susceptibility to either Cry1Ac or Cry2Ab between small-holder and broad-acre farming. The susceptibility to Cry1Ac toxin in northwestern China is higher than that in northern China, while there was no difference for Cry2Ab between northwestern China and northern China. With high levels of adoption of Bt cotton and relatively limited natural refuge for H. armigera, it is important to consider resistance management measures for Bt cotton in northwestern China.

Susceptibility of Helicoverpa armigera to two Bt toxins, Cry1Ac and Cry2Ab, in northwestern China: toward developing an IRM strategy

The invention discloses a cultivation method achieving high yield of multiple cropping silage maize and efficient utilization of water and nitrogen. The cultivation method is characterized by comprising following steps: selecting varieties and drying seeds in the sun; selecting farmland and performing sowing; performing field management at the seedling stage, jointing stage, teaseling and boll opening stage and filling stage. The cultivation method has following beneficial effects: strong operability and high yield of silage maize. By use of the cultivation method, the utilization rate of water and nitrogen is increased; environmental pollution caused by excessive irrigation and fertilization is reduced; economic benefit and social benefit are remarkable; the purposes of high yield, water conservation, fertilizer conservation, and efficient utilization of water and nitrogen of multiple cropping silage maize under drip irrigation are achieved. The cultivation method plays a great role in breaking through the limitation of water resources on bi-annual planting under drip irrigation in northern Xinjiang.

Cultivation method achieving high yield of multiple cropping silage maize and efficient utilization of water and nitrogen

Agronomy Journa l • Volume 109, I s sue 6 • 2017 The Xinjiang Uygur Autonomous Region of China, an important cotton-growing region, is a typical irrigated arid area. Film covering and drip irrigation techniques have been employed since the early 1990s. Consequently, a unique technique of drip irrigation under plastic mulch fi lm (Hu and Li, 2003) was developed in Xinjiang through long-term practice. Th e features of water and fertilizer supply, that is, “low intensity with high frequency” and the eff ect of mulch fi lm in increasing soil temperature and conserving soil moisture have largely improved the per unit area yield of cotton (Jian et al., 2007; Rao et al., 2016). Th e cotton area in Xinjiang in 2014 (242 × 104 ha) was six times that of the 1990s (Statistical Bureau of Xinjiang Uygur Autonomous Region, 1990–2014). Currently, more than 50% of Chinese cotton production is supplied by Xinjiang, and more than 85% of the cotton fi elds in this region are covered with plastic mulch (Bai et al., 2015). However, the continuous use of mulch fi lm for years has led to increasingly serious pollution of mulch fi lm residue and has signifi cantly infl uenced cotton yield and soil production. Research fi ndings suggest that mulch fi lm residue in the cotton fi elds of Xinjiang has reached 18 kg ha–1 per year (Liang and Wang, 2012; Yan et al., 2008), and the average amount of fi lm residue in the soil aft er 20 yr is as high as 300.65 ± 49.32 kg ha–1 (Yan et al., 2008). If mulch fi lm is used for 68 yr consecutively (38 yr from now) without timely regulating measures, the mulch fi lm residue will reach 1 Mg ha–1 (Dong et al., 2013). Th e presence of a large amount of mulch fi lm residue in soil hinders the movement and distribution of water and N, obstructs the growth of crop roots (Li, 2016; Yang et al., 2016) and causes deterioration of soil physical-chemical properties, water maldistribution and soil nutrient decline. When the density of mulch fi lm residue reaches 2 Mg ha–1, alkali-hydrolyzale N and rapidly available P will decrease by 55.0 and 60.3%, respectively (Dong et al., 2013). Pollution control of mulch fi lm residue has become an urgent issue for agricultural production in Xinjiang and even the whole arid region. Currently, there are two major approaches for this issue: (i) the use of degradable mulch fi lm Cotton Root Morphology and Dry Matter Accumulation at Different Film Removal Times

Cotton Root Morphology and Dry Matter Accumulation at Different Film Removal Times

The invention discloses a method for cultivating stored green corn through no-tillage multiple-sowing after wheat growing under drip irrigation conditions, belongs to methods of crop planting and mainly solve the problems of annual optimized allocation and high-efficiency utilization of optothermal resources in the Northern Xingjiang region, improving utilization rate of land and prompting development of animal husbandry, resource utilization of crop straw and stability of an agricultural ecologic system. The method includes that existing sowing technology is adopted to sow winter wheat, row spacing is adjusted, and row spacing of wheat rows waiting for multiple-sowing is expanded to be 20cm for the benefit of operation of a no-tillage sower, so that density and orderliness of multiple-sowing crop are guaranteed, and high yield of the multiple-sowing crop is facilitated; spacing in the rows and spacing between the rows of the multiple-sowing crop after adjustment are conducive to high-efficiency utilization of water. Experiments show that by the method, yield of the multiple-sowing crop is increased by 11.9% when compared with that of conventional tillage flood irrigation, water consumption in the growth period is saved by 31.8%, and water utilization efficiency is improved by 49.1%. The method is suitable for the Ili region and vast Northern Xingjiang region along the Urumchi-Ili Highway on the Northern slope of the Tianshan Mountain, and a scientific method is provided for reform on the cropping system of the Northern Xingjiang.

Method for cultivating stored green corn through no-tillage multiple-sowing after wheat growing under drip irrigation conditions

The photosynthetic parameters of cotton plants may be modified by the timing of film removal during their growing period. This study was undertaken during 2015–2017 in Xinjiang, China, to determine to what extent the film mulching removal time, 1 and 10 days before the first irrigation and 1 day before the second irrigation after seedling emergence, influenced cotton’s photosynthetic characteristics. The control group (CK) was film-mulched throughout the growth stages. The results suggested the following: (1) Removing mulching-film within 50 days since seedling emergence had adverse effects on soil temperature and moisture. (2) Film-removal before the first or second irrigation after emergence improved the net photosynthetic rate in cotton’s later flowering stage and its transpiration rate in mid and later flowering stages while enhancing the actual electron transport rate (ETR) and maximum electron transfer rate (ETRmax) between cotton photosystems I and II. (3) Film-removal treatment also increased cotton plants’ tolerance to high irradiation after emergence, the trend was more pronounced in the early flowering stage in wetter years. (4) Leaf area index (LAI) of cotton was reduced in the film-removal treatment for which the least accumulation of dry matter occurred in a drought year (i.e., 2015). (5) Film removal caused a yield decrease in the dry year (2015), and the earlier the film was removed, the more seriously the yield decreased. Removing mulching film before the second irrigation could increase the yield of XLZ42 in the rainy year (2016) and the normal rainfall year (2017). Early film removal can increase the yield of XLZ45 in the rainy year (2016). Collectively, our study’s experimental results indicate that applying mulch film removal at an appropriate, targeted time after seedling emergence had no adverse effects on soil moisture and temperature, and improved the photosynthetic performance of cotton, thus increased cotton yield and fiber quality, but no significant difference was reached.

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Photosynthetic characteristics of cotton are enhanced by altering the timing of mulch film removal

The invention discloses a method for planting no-tillage reseeded feed rape after winter wheat in Xinjiang region. The method is characterized by comprising the following steps: no-tillage: selectinga way of one-on-four as a previous crop wheat seeding method, and choosing a wheat field plot in which planting is performed at the equal row spacing of 12 cm; seeding: controlling the row spacing ofthe reseeded feed rape to be 36+24 cm; seeding date and seeding rate: controlling the seeding rate to be 9-15 kg hm , evenly mixing according to a ratio of 1 kg of seeds to 10 kg of calcium superphosphate during seeding, and controlling the seeding depth to be less than or equal to 1 cm; naturally backfilling soil after seeding; carrying out irrigation and fertilization, chemical weeding and pest control; field harvesting: (1) using a mechanical harvesting way, mixing the rape with corn stalks (wheat stalks) according to a ratio of 3 to 7 and then ensiling; (2) using the product as green manure, turning over and ploughing into the soil for returning to a field when the seedling heights are about 30-50 cm, and then tamping; (3) directly pasturing, specifically, directly pasturing in theearly flowering stage of the feed rape, and returning livestock manure to the field.

Xiangkun Yang

Papers

Cotton Root Morphology and Dry Matter Accumulation at Different Film Removal Times

Method for cultivating stored green corn through no-tillage multiple-sowing after wheat growing under drip irrigation conditions

Photosynthetic characteristics of cotton are enhanced by altering the timing of mulch film removal

Method for planting no-tillage reseeded feed rape after winter wheat in Xinjiang region