Soil Chemical Analysis

Agriculture consumes more than two thirds of the total freshwater of the planet. This issue causes substantial conflict in freshwater allocation between agriculture and other economic sectors. Regulated deficit irrigation (RDI) is key technology because it helps to improve water use efficiency. Nonetheless, there is a lack of understanding of the mechanisms with which plants respond to RDI. In particular, little is known about how RDI might increase crop production while reducing the amount of irrigation water in real-world agriculture. In this review, we found that RDI is largely implemented through three approaches: (1) growth stage-based deficit irrigation, (2) partial root-zone irrigation, and (3) subsurface dripper irrigation. Among these, partial root-zone irrigation is the most popular and effective because many field crops and some woody crops can save irrigation water up to 20 to 30 % without or with a minimal impact on crop yield. Improved water use efficiency with RDI is mainly due to the following: (1) enhanced guard cell signal transduction network that decreases transpiration water loss, (2) optimized stomatal control that improves the photosynthesis to transpiration ratio, and (3) decreased evaporative surface areas with partial root-zone irrigation that reduces soil evaporation. The mechanisms involved in the plant response to RDI-induced water stress include the morphological traits, e.g., increased root to shoot ratio and improved nutrient uptake and recovery; physiological traits, e.g., stomatal closure, decreased leaf respiration, and maintained photosynthesis; and biochemical traits, e.g., increased signaling molecules and enhanced antioxidation enzymatic activity.

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Regulated deficit irrigation for crop production under drought stress. A review

Intelligence has been considered as the major challenge in promoting economic potential and production efficiency of precision agriculture. In order to apply advanced deep-learning technology to complete various agricultural tasks in online and offline ways, a large number of crop vision datasets with domain-specific annotation are urgently needed. To encourage further progress in challenging realistic agricultural conditions, we present the CropDeep species classification and detection dataset, consisting of 31,147 images with over 49,000 annotated instances from 31 different classes. In contrast to existing vision datasets, images were collected with different cameras and equipment in greenhouses, captured in a wide variety of situations. It features visually similar species and periodic changes with more representative annotations, which have supported a stronger benchmark for deep-learning-based classification and detection. To further verify the application prospect, we provide extensive baseline experiments using state-of-the-art deep-learning classification and detection models. Results show that current deep-learning-based methods achieve well performance in classification accuracy over 99%. While current deep-learning methods achieve only 92% detection accuracy, illustrating the difficulty of the dataset and improvement room of state-of-the-art deep-learning models when applied to crops production and management. Specifically, we suggest that the YOLOv3 network has good potential application in agricultural detection tasks.

CropDeep: The Crop Vision Dataset for Deep-Learning-Based Classification and Detection in Precision Agriculture.

Multi-site assessment of the effects of plastic-film mulch on the soil organic carbon balance in semiarid areas of China

https://ris.utwente.nl/ws/files/70061104/waterscarcity.pdf

Water scarcity alleviation through water footprint reduction in agriculture: The effect of soil mulching and drip irrigation

Agriculture in rainfed dry areas is often challenged by inadequate water and nutrient supplies. Summerfallowing has been used to conserve rainwater and promote the release of nitrogen via the N mineralization of soil organic matter. However, summerfallowing leaves land without any crops planted for one entire growing season, creating lost production opportunity. Additionally, summerfallowing has serious environmental consequences. It is unknown whether alternative systems can be developed to retain the beneficial features of summerfallowing with little or no environmental impact. Here, we show that diversifying cropping systems with pulse crops can enhance soil water conservation, improve soil N availability, and increase system productivity. A 3-yr cropping sequence study, repeated for five cycles in Saskatchewan from 2005 to 2011, shows that both pulse- and summerfallow-based systems enhances soil N availability, but the pulse system employs biological fixation of atmospheric N2, whereas the summerfallow-system relies on ‘mining’ soil N with depleting soil organic matter. In a 3-yr cropping cycle, the pulse system increased total grain production by 35.5%, improved protein yield by 50.9%, and enhanced fertilizer-N use efficiency by 33.0% over the summerfallow system. Diversifying cropping systems with pulses can serve as an effective alternative to summerfallowing in rainfed dry areas.

/pdf/diversifying-crop-rotations-with-pulses-enhances-system-3ihy0ohdyj.pdf

Diversifying crop rotations with pulses enhances system productivity.

Water scarcity, water pollution, and water-related waste threaten humanity globally, largely due to the limited supply of freshwater on the planet, the unbalanced distribution of water resources, and the excessive consumption of water from the growing population and its economic development. China is facing severe water shortages; the northern part of the country has an average freshwater availability of 760 cubic meter per capita per year, 25% below the internationally accepted threshold for water scarcity. Agriculture in northwest China relies on annual precipitation of 50–500 mm, 70% of which occurs from July to September, and annual evaporation from 1500 to 2600 mm. In the Hexi Corridor regions where annual precipitation is below 150 mm, farming largely depends on irrigation with water from Qilian Mountain snowmelt. However, permanent snow on the mountain has moved upwards at a rate of 0.2–1.0 m annually, and groundwater in the valley has declined at a rate of 0.5–1.8 m year−1. Consequently, some natural oases, along the old Silk Road, have shrunk or disappeared and wells have dried up. At the meantime, some farms use irrigation water at a rate as high as 11,000 m3 ha−1, much greater than crop water requirements for high yield. In recent years, many innovative research projects have dealt with the water issue in arid and semiarid northwestern China. In this chapter, we summarize some key water-saving technologies developed from some of these recently completed research projects, and discuss integrated and innovative approaches for the development of water-saving agricultural systems. Our goal is to encourage the use of innovative water-saving technologies to reduce agricultural water use, increase crop water-use efficiency, and improve agricultural productivity.

Water-saving innovations in Chinese agriculture

Diversifying crop rotations with pulses enhances system productivity

Soil quality indicators (SQI) can be used as a synthetic tool for the assessment of the sustainability of agricultural systems. In this study, we developed SQI using minimum data set (MDS) and determined the response of SQI to long-term tillage systems. Field pea (Pisum sativum L.) and spring wheat (Triticum aestivum L.) were grown in alternate years at northwestern China, and soil attributes and crop productivity were measured 6 years after the initiation of the experiment. The MDS used to develop the SQI included soil physical (aggregate, bulk density, capillary porosity, field capacity), chemical (soil organic matter, total nitrogen, available phosphorus, available potassium) and biological (microbial count, microbial biomass, and the activities of catalase, urease, alkaline phosphatase, and invertase) properties. All the property variables were measured in each of the 0–5, 5–10 and 10–30 cm depths and those variables that contributed significantly to the SQI were selected to be included in the MDS. Amongst the measured variables, bulk density and microbial counts occurred in the MDS of all the three depths, suggesting that these two properties are highly affected by the tillage treatments. In the long-term field experiment, the no-till with stubble covering the soil surface treatment received the greatest SQI score and achieved the highest crop yield. Soil quality under tillage systems can be assessed adequately using MDS measured at the top soil (0–5 cm) layer in rainfed agro-ecosystems.

Yining Niu

Papers

Regulated deficit irrigation for crop production under drought stress. A review

Diversifying crop rotations with pulses enhances system productivity.

Water-saving innovations in Chinese agriculture

Diversifying crop rotations with pulses enhances system productivity

Soil quality indicators and crop yield under long-term tillage systems