Navigating water and nitrogen practices for sustainable wheat production by model-based optimization management systems: A case study of China and Pakistan
Shah Jahan Leghari, Yu Zhang, Aijaz Ahmed Soomro, Muhammad Rizwan Shoukat, M.F.M. Zain, Yichang Wei, Qiang Xu, Mahmooda Buriro, Tofique Ahmed Bhutto, Rajesh Kumar Soothar, Yaseen Laghari, Abdul Hafeez Laghari
Abstract
Water and fertilizer losses have often affected wheat yield per unit area in China and Pakistan. The 2-year field experiments were conducted at six research stations. The experimental sites in China were Tongzhou, Qiliying and Yuanyang. In Pakistan were Faialsaabad, TandoJam and Dokri. Fertilizer treatments were: N 275 , N 207 and N 135 kg ha −1 in Tongzhou and N 125 , N 105 and N 90 kg ha −1 in Faisalabad. While the irrigation treatments were: W 210–230 , W 160–190 and W 110–140 mm ha −1 in Qiyliying, W 350 , W 305 and W 250 mm ha −1 in Yuanyang, W 435 , W 400 and W 365 mm ha −1 in TandoJam and W 380 , W 340 and W 300 mm ha −1 in Dokri. The grain yields, water and N losses were simulated using the WHCNS model. The model showed a good ability to capture the effects of management practices and read the environmental diversity. The study revealed that major contributors to water and N losses were N leaching ( r =0.98), evaporation and drainage ( r =0.77–0.96) rates. In Tongzhou, the N 207 treatment maintained yield, NUE and decreased N loss. In Faisalabad, the N 125 increased yield but led to higher N loss and reduced NUE. Furthermore, the decline in surface soil water content was a common issue in Pakistani sites and wheat yields were 27.48–41.60 % lower than in China. In Qiliying, the W 160–190 and W 110–140 and in Yuanyang, the W 300 and W 250 treatments decreased the annual average water loss by 33.49–12.38 mm and 66.06–55.01 mm, respectively. In TandoJam, the W 400 and W 365 and in Dokri, the W 380 and W 340 treatments decreased water loss by 72.34–45.87 mm and 56.84–37.82 mm compared to the full irrigation amount. Overall, results showed that 17.39–23.81 % of water use could be decreased without yield penalty in Qiliying and 14.29 % in Yuanyang. In Pakistani sites of TandoJam and Dokri, a decreased irrigation amount of 10.5 % is recommended. • Determined water and N losses in China-Pakistani wheat production systems. • We demonstrate the potential use of the WHCNS model in China-Pakistani environment. • We measured wheat yield difference between China and Pakistani agriculture systems.