Core Ideas• A sensor threshold of -90 kPa resulted in net returns that were $142/acre greater than the producer standard.• A sensor threshold of -90 kPa increased IWUE at least 61% relative to -50 and -130 kPa thresholds.• Neither increasing nor decreasing the threshold as a function of growth stage improved yield relative to a season-long threshold of -90 kPa.

Properly terminating furrow irrigation in mid-southern United States (U.S.) crops could reduce irrigation costs, the likelihood of adverse harvest conditions, and agricultural withdrawal from the Mississippi River Valley Alluvial Aquifer (MRVAA). This research was conducted to determine an optimum termination window for furrow-irrigated cotton (Gossypium hirsutum L.) in the mid-southern U.S. The effects of irrigation termination timing on cotton lint yield, net returns, and irrigation water use efficiency (IWUE) were evaluated on a Leeper silty clay loam (fine, smectitic, nonacid, thermic Vertic Epiaquepts) and on a Dundee silty clay (fine-silty, mixed, active, Typic Endoaqualfs). Neither terminating nor continuing to irrigate cotton from cutout (NAWF = 5) up to three weeks past first cracked boll had an effect on lint yield or fiber quality (p ≥ 0.6107). Irrigation water use efficiency declined when water was applied past cutout (p < 0.0001). Results indicate that irrigation in cotton can be terminated at cutout without adversely effecting lint yield and fiber quality if soil water potential does not exceed -130 kPa prior to first cracked boll. Terminating irrigation in cotton at cutout could reduce late season irrigation cost and reduce water withdrawal from the MRVAA thus improving it sustainability.

The Mississippi River Valley Alluvial Aquifer is declining at a rapid rate due to withdrawal for agricultural irrigation. This research was conducted to develop a sensor‐based irrigation threshold for cotton that maximizes net returns and irrigation water use efficiency. Earn 1 CEU in Soil & Water Management by reading this article and taking the quiz at http://www.certifiedcropadviser.org/education/classroom/classes/727.

Standard row spacing for peanut (Arachis hypogaea L.) in Georgia is 91-cm in a single-row pattern. Narrower row spacings are often used in crops grown in rotation with peanut. Therefore, converting peanut to narrower row spacing may be easier and beneficial to some growers if cultivars and seeding rates can be identified that can be grown in narrow rows without a reduction in yield and grade. Based on current University of Georgia recommendations, peanut is typically planted at 19 seed/m with a 91-cm row spacing. Using narrower row spacing and constant seeding rates, increased seed costs would be observed. The objectives of this research were to evaluate the influence of cultivars and seeding rate in peanut planted in 76-cm single rows on yield, grade, and tomato spotted wilt virus (tospovirus) (TSWV) incidence. Experiments were conducted in 2008, 2010, and 2014 in Tifton, GA and in 2014 at Camilla, GA. Treatments were comprised of three cultivars (varying each year) and three seeding rates (14, 17, and 19 seed/m). Results indicate that pod yield, grade, and TSWV incidence were not affected by seeding rate. Seeding rate significantly influenced plant density where 14, 17, and 19 seed/m seeding rates resulted in 12.1, 13.2, and 13.8 peanut plants/m, respectively equating to a 9% and subsequent 4% increase in plant density as seeding rate increased. Seeding rate did not affect the rate of canopy closure, but cv. Georgia-12Y and TUFRunner e '511' had faster canopy closure than Georgia-06G. Peanut grade (total sound mature kernels) was not influenced by seeding rate, but did differ between cultivars. From these results, it can be concluded that 76-cm single-row can provide adequate yield and grade across multiple seeding rates. In addition, this study confirms that cultivar selection is the primary means for reducing TSWV incidence and altering grade in 76-cm peanut production.

There is limited adoption of irrigation scheduling tools that could improve application timing and water use efficiency in row‐crop production systems common to the mid‐southern United States. The objectives of this manuscript are to describe a sensor‐based irrigation scheduling method and review its effects on water applied and crop productivity. The effects of scheduling irrigation based on the recommended construction, deployment, and utilization of the WATERMARK 200SS granular matrix (WATERMARK) sensor on water applied, crop productivity, and crop water use efficiency were reviewed for corn (Zea mays L.), soybean [Glycine max L. (Merr.)], peanut (Arachis hypogaea L.), and cotton (Gossypium hirsutum L.) produced in the Prairie region of Arkansas and the Delta regions of Arkansas and Mississippi. For corn and soybean, on‐farm research indicates the recommended irrigation threshold of −85 to −100 cbar reduces total water applied up to 40% while maintaining or improving yield up to 3%, net returns up to $39 acre−1, and irrigation water use efficiency up to 51% for soil textures ranging from very fine sandy loam to clay. Similarly, for peanut and cotton, results indicate the irrigation threshold that minimizes water use while maximizing yield and net returns is −50 cbar and −100 cbar, respectively. The recommended method for scheduling irrigations with a WATERMARK 200SS soil moisture sensor promotes the efficient use of water in row‐crop production systems common to the mid‐southern USA.