Soil water uptake is a function of root growth and distribution. Therefore, restrictions on root system growth may reduce water and nutrient uptake, which results in slower plant growth. The objective of this study was to determine the effects of different irrigation strategies, nitrogen application rates, and planting methods on the winter wheat root growth. The experimental factors included two irrigation strategies (variable alternate furrow irrigation defined as partial root-zone irrigation and ordinary furrow irrigation), two planting methods (in-furrow planting and on-ridge planting), and three nitrogen (N) application rates (0, 150, and 300 kg N ha⁻¹) in 2015–2016 and 2016–2017 growing seasons. Results indicated that the in-furrow planting decreased mean root length density and root mass density (8% and 10%, respectively, in the fertilized treatments) compared to that obtained in the on-ridge planting. The partial root-zone irrigation reduced root length density by about 5% and 7% in the fertilized treatments compared to that obtained in full irrigation in the first and second year, respectively; however, these reductions were not statistically significant. Furthermore, the results implied that nitrogen fertilizer application increased root length density by 48% and 24% in the first and second year, respectively. Likely, root mass density increased by 32% and 5% in the first and second year, respectively. The exponential decaying relationship between root length density and soil depth indicated that the in-furrow planting with 300 kg N ha ⁻¹ produced the highest root density at the soil surface layer and reduced deep root penetration compared to the on-ridge planting and the other N treatments. Further analysis revealed that grain yield linearly correlated with root length density and root mass density in the first year. However, a polynomial (quadratic) relationship was obtained in the second year. Consequently, increasing the main root traits, including root length and root mass, enhanced winter wheat grain yield until it reached a threshold value. Higher values negatively affected grain yield, which might be due to allocating carbon to roots instead of grains.

土壤吸水量是根系生长和分布的函数。因此，限制根系生长可能会减少水分和养分的吸收，从而导致植物生长变慢。这项研究的目的是确定不同灌溉策略，施氮量和种植方法对冬小麦根系生长的影响。试验因素包括两种灌溉策略（可变交替沟灌定义为部分根区灌溉和普通沟灌），两种种植方法（沟内种植和垄上种植）以及三种氮素（N）施用率（0 ，150和300 kg N ha ^-1）在2015–2016和2016–2017生长季节。结果表明，与垄上种植相比，犁地种植降低了平均根长密度和根质量密度（在施肥处理中分别降低了8％和10％）。与第一年和第二年的完全灌溉相比，部分施肥的根系分别减少了分别约5％和7％的根长密度。但是，这些减少在统计上并不显着。此外，结果表明，氮肥的施用在第一年和第二年分别使根长密度增加了48％和24％。第一年和第二年，根质量密度可能分别增加了32％和5％。与垄上种植和其他N处理相比，^-1在土壤表层产生最高的根系密度，并减少深根系渗透。进一步的分析表明，第一年谷物产量与根长密度和根质量密度线性相关。但是，第二年获得了多项式（二次）关系。因此，增加主要根系性状（包括根长和根质量）可提高冬小麦籽粒产量，直至达到阈值。较高的值会对谷物产量产生负面影响，这可能是由于将碳分配给根而不是谷物。