Field experiments were conducted to study soil properties, soil enzymes activities, water use efficiency (WUE) and crop productivity after six years of soya bean straw mulching in the semi‐arid conditions of China. The experiment included four treatments: CK (Control), N (240 kg N ha‐1), H (soya bean straw mulching at half rate 700 kg ha‐1 with 240 kg N ha‐1) and F (soya bean straw mulching at full rate 1,400 kg ha‐1 with 240 kg N ha‐1). Soil organic carbon (SOC), soil labile organic carbon (LOC), soil available N (AN), available P (AP) and enzyme activities were analysed after wheat harvesting in 2016 and 2017. Results show that straw amounts had positive effects on the soil fertility indices being higher for treatment F. The SOC, LOC, AN, AP and enzyme activities (i.e. saccharase, urease and alkaline phosphatase) were in the order of F > H > N > CK. High wheat grain yield and WUE were observed for F treatment. A total of six years mulching along with 240 kg ha‐1 nitrogen fertilizer application is sufficient for wheat yield stability and improving soil properties except urease activities in the semi‐arid condition of China. However, the straw mulching amount should be further studied with minimum nitrogen fertilizer for an environment‐friendly and effective approach for improving the soil biological properties with adequate crop production on a sustainable basis in the semi‐arid region of China.

Field experiments were conducted to determine the effect of composts prepared from different organic materials with rock phosphate (RP) on yield and P uptake of berseem and their residual effect on maize crop (cv. Azam) during 2011-2012. Composts prepared from RP fed farm yard manure (FYM), simple FYM, organic waste and city garbage were applied at the rate based on their P concentrations. Composts significantly (P ≤ 0.05) increased total dry matter weight of Berseem in first and second cut over control. Residual effect of the prepared composts was determined on yield and plant P uptake of maize in the same layout of Berseem. Maximum and significantly (P ≤ 0.05) higher maize grain yield, total dry matter yield and stover yield of 3161 kg•ha −1 , 9633 kg•ha −1 and 6472 kg•ha −1 , respectively were recorded by the residual effect of compost of organic waste with half dose of SSP. Thousand grains weight of 220 g was noted in the treatment of residual effect of compost of RP fed FYM with half dose of SSP. Post harvest soil N and P concentrations improved with composting. Significant (P ≤ 0.05) increases in N and P uptake by berseem and maize plants were observed with added composts. Results suggest that the use of composts prepared from different organic materials with RP is environmental friendly and has potential to improve crops yield and plants N and P uptakes for a prolonged time.

This study was conducted with the aim of finding humic acid and crop residues effects on soil and wheat nitrogen at New Development Farm, University of Agriculture, Peshawar, Pakistan during winter 2009-2010. The experiment was laid out in RCB design having four replications. Different levels (1, 1.5, 2 and 2.5 kg ha −1 ) of Humic acid were applied at sowing time. Mungbean (5 tons ha −1 ), wheat straw (10 tons ha −1 ) and mungbean (2.5 tons ha −1 ) + wheat straw (5 tons ha −1 ) were incorporated 30 days before sowing. Our results showed higher mineral and total nitrogen (7.32 and 0.43, respectively) mg kg −1 in soil and also higher nitrogen in stem, leaves and grains (2.3, 4.6 and 21.1, respectively) mg kg −1 at maturity in those plots in which 2.5 kg ha −1 of humic acid was applied. Higher mineral and total nitrogen (7.04 and 0.5, respectively) mg kg −1 in soil and also higher nitrogen in leaves (5.5) mg kg −1 at pre-anthesis, while at maturity stage in stem, leaves and grain (5.5, 2.1, 4.2 and 20.8) g kg −1 was recorded in those plots in which 5 tons ha −1 mung bean was incorporated. Our experimental results suggest the use of 5 tons ha −1 of mungbean residues with 2.5 kg ha −1 of humic acid to improve soil fertility availability of more nitrogen in wheat plants to increase the crop yield and grains quality.

Inducing tolerance against drought stress with plant growth regulator and plant nutrients is vital for ensuring food security and sustainable crop production. The present study was undertaken to assess the influence of salicylic acid (SA) either seed primed or foliar application (1.1, 2.2, 0.7 and 1.4 mM SA) coupled with potassium (K) fertilisation (0, 50 and 100 kg/ha) on wheat yield and nutrients uptake under drought stress (100% field capacity [FC], 60% FC, 30% FC) at tillering stage. Findings revealed that drought stress substantially reduced yield components, yield and grain nutrients content and uptake, whereas the potassium use efficiency (KUE) and antioxidant profile was improved. However, the foliar application of 0.7 mM SA and 1.1 mM SA as seed priming had increased number of spikes, thousand grain weight, grains per spike, grain and biomass yield, N, P, K content and K uptake, KUE and antioxidant profile both under no stress and drought stress treatments indicating the key role in ameliorating the ill effects of drought stress as compared with no SA application. Moreover, K fertilisation at 100 kg/ha had improved growth, yield and yield components, plant nutrient uptake and antioxidant profile except proline under both no stress and mild stress as compared with no K application. These results suggested that the combined use of SA either as foliar or seed primed with higher K fertilisation can substantially improve wheat yield, and grain nutritional content under mild and severe drought stresses.

Canola crop has the potential for both seeds and grazing. Optimal planting density, time of nitrogen (N) fertilizer application and rates are the major aspects for successful qualitative traits and canola yield formation. In this content, optimization of planting density, N levels and its time of application in dual purpose canola are needed. This study was carried out in RCB design with split pot arrangement having three repeats during winter 2012–2013 and 2013–2014. The study evaluated N levels (120 and 80 kg N ha−1), cutting treatment, N application timings and planting density (20 and 40 plants m−2) effects on qualitative traits and yield of canola. No-cut treatment had 7.02%, 2.46%, and 4.26% higher, glucosinolates, oil, and protein content with 31.3% and 30.5% higher biological and grain yield respectively, compared with grazed canola. Compared with no-cut canola, grazed canola resulted in 7.74% of higher erucic acid. Further, application of N at 120 kg N ha−1 had 8.81%, 5.52%, and 6.06% higher glucosinolates, percent protein, and seed yield, respectively than 80 kg N ha−1. In-addition, the application of N into two splits was most beneficial than the rest application timings. Cutting had 15% reduction in grain yield of canola and fetched additional income of 143.6 USD compared with no-cut. Grazing resulted in a 23% reduction in grain yield while had additional income of 117.7 USD from fodder yield. Conclusively, the application of N in two splits at 120 kg N ha−1 combined with 20 plants m−2 is a promising strategy to achieve good qualitative attributes and canola yield under dual purpose system.